My friend faced similar problem. Apparently in his case, after the exam (even after accepting the scores), he could not get the unofficial score report as the test center was having trouble connecting with cloud server which prints the report. After having a talk with the exam center, they said they'll raise an issue and after contacting the customer support of mba.com, they said they will send the unofficial scores within 4-5 business days by mail.
But tbh, since you'll likely have your Official GMAT Score in the next 7-14 days and THAT is what actually matters. Since you're aware of your unofficial score, you already know what your official result will be. I would suggest you to wait unless you need the unofficial score report for anything specific.
Good luck, meanwhile.