Extremely bad customer service, sim disconnected without a clear explanation and answers.

I've heard my prepaid sim for years, out of nowhere I can't make use of it anymore it has been suspended due to that my contract has ended which I've never had nor received the benefits. When I ask for assistance that's all they can tell me they can't tell me who requested and signed for the contract also when now my number is blocked which is an inconvenience and the consultant asked me why didn't I complain when I got the contract benefits which I never received.