Poor service and false advertising very bad after service

I had a contact with cellc if i remember correctly it was 2021 if not 2020 so i then added another one of the same phone and i asked them over the phone that they shouldn't add anything extra on the package i was supposed to pay R449 a month So the very first month the installment was wrong called them they said they will fix it and they did not instead they money kept going up till i started reversing the money still that didn't help they then closed the sim cards Came back to them and made an arrangement as they have handed me to nimble to pay R250 every month of which i did But early this year around March i get a call from nimbles that cellc handed me over to them for collection yet i was handed over already and arrangement was the there they now want me to pay R8500 for services that i never used