Why can't i sign into my t-mobile acct with my cell phone?

[Chris]

I've been a customer of t-mobile for quite a long time and ever since i can remember i haven't been able to sign into my acct on their website. every time i call them to see about them fixing this i keep gettin the same results.."everything is working on their end of it!" they tell me its been resolved and that i can now browse my acct through their website. but its still not working! i'm so frustrated that i'm about ready to pull my hair out or throw the DAMN phone across the room and smash it against the nearest wall!! can someone please help me with this? i don't know what to do