Cannot cancel my contract with Vodacom!

I had a contract with Vodacom up to April, 2025. This is almost December and they cannot cancel the contract and make it a prepaid line. Everytime I make a full payment to clear the bill, they come up with another story. Now, they say it might be converted after 2 more invoices. And the customer agent even has the audacity to say I am lying! What a tool!

It is easy to get into a contract with Vodacom but cancelling it like a nasty divorce. Eish! Why are they allowed to do this to customers?