Metro Pcs Store Service rep lied to my face Antioch, California

Last Febuary, we had our phone activated on the 28th. Since I get paid on the first of the month, I was told that I would have to go to the main office to change billing date, at a cost of ten dollars. I didn't have a car, so I paid $54 a month instead of the $42.97. Well I went to the main office to have billing date, name corrected on March 1, 2010. The service rep stated no problem, that it was effective imediately. Then on April 20th, received a Metro text to pay the $42.97 by the 27th. I went back, showed the same rep the message. She then said the only way the billing date, name correction can be changed is if the phone stays off for seven days or buy a new phone. By that time I would owe more money. I couldn't get a hold of anyone at the 1800 numbers, or go into my account online. This is the only phone I have. I guess they want to make extra money. My plan is forty a month, not 54