Cellphone contract

My contract ended in October 2021, I called in on numerous occasions to cancel was even advised by different agents that the contract ended. Yet they are still debiting, clearly they are refusing to end the contract after I’ve made it clear that I no longer need anything from them. I don’t want their minutes or data, mtn is keeping me hostage because I want nothing to do with them. I don’t want your damn data or minutes, just cancel the ****** contract for ****s sake!