My mom, a T-Mobile customer for over two years, recently changed her plan and got a new phone. She did this in a store and had no problems, they put the old sim card in the new phone, Samsung T209 and sent her on her way. Question, her sim was well over two years old....shouldn't they have given her a new sim? Has Tmobile made changes to their sim cards over the past two years? I know Cingular has. Thanks in advance.