SBA inquiry from a senator or congressman works every single time. Local SBA is absolutely useless. Just find the senator's office closest to the business, call them up, and say that you are looking to launch an inquiry against the SBA regarding EIDL. They will take down your email and send a consent form. When you send the consent form, include a DETAILED write-up on the issue and how you have tried to fix the issue but the application just seems stuck.

I have a perfect batting average with this process