Getting clients into contracts they know nothing about!!!! RMCS

So I found out from Vodacom that I was in a contract with RMCS, recently I lost my phone and in order for me to get a sim swap I need to cancel that contract. I have called RMCS numerous times and they said they would cancel it with 2 days, it’s been over a week and they haven’t cancelled it. I really need my number cause I’ll miss deliveries that I’m supposed to receive. This is really an inconvenience I can’t afford.