We believe that improved customer service is the best way for us to

I would really appreciate if someone can comment on the essay and rate it out of 6 . Please help me in finding any grammatical/logical/structural or any other error.I have gmat in 2 days fingers crossed.

The following appeared in a memo from the customer service division to the manager of Mammon Savings and Loan.
“We believe that improved customer service is the best way for us to differentiate ourselves from competitors and attract new customers. We can offer our customers better service by reducing waiting time in teller lines from an average of six minutes to an average of three. By opening for business at 8:30 instead of 9:00, and by remaining open for an additional hour beyond our current closing time, we will be better able to accommodate the busy schedules of our customers. These changes will enhance our bank’s image as the most customer-friendly bank in town and give us the edge over our competition.”
Discuss how well reasoned... etc.

The argument, that the improved customer service will enhance the image of the Mammon Savings and Loan as the most customer-friendly bank and that this better customer service will give the company an edge over competition omits some important considerations that need to be addressed to get a holistic view of the situation under considerations. The argument fails to provide substantive evidence or sound reasoning to be able to prove or even support the conclusion form the given premises. The major flaws in the argument include unstated assumptions as well as the fact that argument considered improved customer service the leading contributor in getting edge over competition. The passage below aims to elaborate on the flaws as well as provide potential remedies to resolve them.
First of all, the argument readily assumes that customers consider current wait time in teller lines, current opening time and current closing time as the potential issues with customer service of the bank. This is an unwarranted leap of faith that needs additional evidence in order to hold. A possible situation that contradicts this assumption could be that customers think that current wait time, opening time and closing time are not an issue at all and that bank lacks in its ability to offer variety of loans and other savings options. Another possibility might be that the customers think that the mobile and web support are the two important customer service means that the bank currently lacks. Moreover, the customer service division of the bank could be performing very well as compared to its competitors but the bank does not have more number of branches as compared to its competitors. Hence, the conclusion is invalid unless the argument provides additional evidence to validate this unstated assumption.
Secondly, the argument claims that wait times, changes in opening and closing hours will lead to edge over competition. This is again a weak and unsupported claim as the argument does not take into account that customers of the bank already are satisfied with the wait time and opening and closing hours, and that customers main concerns is the rude behavior of the customer service representative. For example, since most of the bank's branches are located in an area where majority of the customers speak only Spanish and since the customer service representatives do not understand Spanish, the representatives end up behaving rude with the customers. Additionally, in the case that the bank is considered customer friendly when the bank's representatives are multi-lingual, then the conclusion will not hold as well. Hence, the argument fails to convince readers that improved customer service will lead to desired results.
Lastly, the argument considered bank's enhanced image as the expected outcome of the improved customer service. What if the bank's image is already tarnished and even after implementing few changes the bank cannot appear as customer-friendly bank? Another possible case might be that customers are not concerned with customer service as much as they are concerned with better rate of interest on their loans. Moreover, if the customers are switching to the bank's competitors because of the higher rate of interest at Mammon Savings and Loan, then the argument would not hold either.
To remedy the aforementioned flaws, the argument needs to include evidence that supports each of the unstated assumptions. Had the argument mentioned that customers think that current customer service is not good, that customers have issues specifically with wait time, opening and closing hours and that the bank is already rated higher in all aspects other than the customer service than its competitors, then the argument would have been much more convincing.

In summary, the argument fails to mention several key factors, on the basis of which it could be evaluated, and fails to reason logically from the given premises. The flaws discussed above renders the argument unconvincing. Had the argument included remedies mentioned above, then the conclusion would have been much more reasonable.