Sprint review: change of account name leads to unauthorized change of plan

the account was originally under my brother's name, so i went to this sprint store to get it under my name. I stated very clear that the only change i wanted was the change of the account holder's name. The staff also made sure to tell me that the ONLY thing being changed was the NAME, NOTHING ELSE. For some reason, now i get my first bill after that, to be surprised by a change stupider than i can think of, which was a complete new Contract, a complete new Plan. SERIOULY? If you think about it, if they would have told me they were changing all OF THIS, do you think i would have agreed for my BILL to INCREASE? i called sprint many times, and spent HOURS, yet they can't even solve a problem that was a result of an employees' lack of explanation. It is pretty obvious to me that the employee that attended me was interested in making a commision for a NEW ACCOUNT, and not to solve my Change of account holder's name. In other words, i wouldnt be this STUPID to change my account holder's name, if they would have explained this BEFOREHAND. i am pretty dissapointed because i've been a loyal customer for around 10 years :( *They literally promised that everything was going to remain the same except the account holder's name. i also have witnesses, i also never received ANY info/copy/anything/verbal warning telling me that my plan and it's price was going to change. Thanks. in less then 30 days im being charged $380 dollars, when i used to pay $120-130 a month. Total SCAM