Vodacom is holding me hostage when I asked to cancel my contract

I was on the phone with vodacom in april changing my contract and was told I will be paying R500 going forward. I got charged wrong. Called Vodacom to tel them to cancel my contract, they didnt. I reversed the debit order as that is not what I agreed to. Went to a branch which also confirmed no contracting was on the system to confirm the new changes!! I AM STILL WAITING FOR MY RECORDED CALLS TO LISTEN TO AND THEY HAVE NOT GOTTEN THEM YET BUT SEND ME TO THE ATTORNEYS FOR COLLECTIONS WHEN THEY CANNOT EVEN HANDLE THIS MATTER?!!! WHY AM I PAYING IF YOU CANNOT GET YOUR THINGS CORRECT?!!