Hi there!
Thanks for getting in touch with us!
In response to your query:
Most B-Schools require 2 Recommendation Letters, in your case we would advice you to try and get in touch with your Old Company and see if any of the previous colleagues or Supervisors can provide an LOR ( even if the said person is in a different Company, it is fine).
The second LOR can be from one of your client's.
In worse case the first option is not possible then you'd need to take 2 LOR' from the Client or Vendor.
Additionally, you may also use the Optional Essay to explain the choice.