[VoiceOps] Can't call 833 numbers from specific rate center via cell phones

I have a new 833 toll free number. Cell phones (both ATT and Verizon) in a specific rate center are not able to call this new number or other 833 numbers. I have contacted my origination provider, ATT wireless, and Verizon wireless, but I am unable to get in contact with the proper people to resolve the issue. Any ideas? Sincerely, Keln Taylor