Worst service experience ever

In 2019 we cancelled our contracts and paid the the cancellation fees off almost R17000.00. Now Vodacom has send us a bill of R7000 because the cancellations was not processed correctly. Proof of payment and acceptance documents was signed and send through. Watch out for this. Just spend time with one of their consultants that cannot help me. Can someone from Vodacom please contact me +***01 before further actions have to be taken.