Vodacom still charging for cancelled contract

I took out 5 data contracts on the same day, was called in December 2018 to upgrade which I did. Called in December 2020 to cancel all 5 and only 3 were cancelled and I called in to query and request an investigation in February and no one got back to me. I have one more contract that still needs to be paid. But the credit has not been done on the other 2 and now I’m being threatened with summons. I called again to Vodacom and no one seems to be able to help. I want to pay what I owe one the one contract