TMOBILE TOO HIGH AND WILL RIP YOU OFF Internet

I HAVE TMOBILE SERVICE AND BOUGHT AN EXPENSIVE PHONE WHICH IS THE MYTOUCH 4G THAT SUPPOSE TO BE THE FASTEST PHONE AROUND I CALLED TMOBILE TO INQUIRE IF I WOULD HAVE TO CHANGE MY DATA PLAN THE REPRESENTIVE STATED WELL YES YOU WILL HAVE TO PAY MORE FOR A PARTICULAR DATA PLAN THATS COMPATIBLE FOR THE PHONE SO...I WAS THINKING WELL I ALREADY HAVE THE MYTOUCH SLIDE AND THE MYTOUCH DATA PLAN WHY WOULD I HAVE TO PAY MORE FOR INTERNET IM ALREADY PAYING 25.00 SHE TOLD ME WELL IF YOU GET THAT PHONE YOU WILL PAY 30.00 INSTEAD AND I RECEIVED THE PHONE TO SEE IF THE INTERNET WORKS AND IT WORKS JUST FINE AS IF ITS ALREADY COMPATIBLE WTH THE PHONE SO BASICALLY IF YOU PURCHASE AN NEW PHONE AND TMOBILE REPS TELL YOU YOU HAVE TO PAY MORE THAN ITS A FIB!!!