4 YEAR OLD CONTRACT

My contract is over 4 years old and does not exist anymore, I am paying an increased fee for a contract that included a free phone. My cost limit with my company is what I am currently paying. All I want is to know why I cant get a new phone on my current contract rate? especially if my contract does not exist anymore?? why charge me more for what I already have?? nobody can answer my question and I have been a MTN client since 1998 in one way or another, this is why I will go elsewhere for a new contract