Verificación de cuenta

I just spent 3.5 hours at TMobile to no avail with about 10 different call center calls as well to no avail with an issue of TMobile saales staff being unable to  access my account. This message comes up:

Failed to get account verification data from server: Error to get Account Verification Data. Could not parse XML.

Why can't any official TMobile folks not know what this?? Anyone have suggestions? Desperate! Thank you.