Disability question: Does anyone know if Premier Disability Services is a credible company?

I recently attained Premier Disability Services for my Social Security Disability appeal. I mailed in all the signed pages for authorizing them to contact all my doctors, employers, medical records, etc. What I am looking for now is whether or not this company is credible. This company is located at 3397 Coon Rapids, Minneapolis, Minnesota 55433, and their phone number is 1–855-773–2727. I have been scammed multiple times in the past by some very good con artists. Never received any reimbursement or leads of finding them. I would appreciate any information you can give me that would help me feel confident that I didn’t make the wrong decision by hiring them. Thank you. Debbie