Bad service

Around November 2020 I call cell c terminating my contracts with were due, the following month I was still billed for the same contracts, when I ask them they insist I only canceled one contract what is puzzling here is that both contracts were due at the same time, I have asked them to send me the recording where I am only canceling one contract. I have been waiting still today, I have been given the reference number no one has gotten back to me. this is so unprofessional, after all the years of being a loyal customer this is the thanks I get.