RCS and MBD harassment

I had a load with RCS, my bank account was debited on monthly basis till I pay a lump sum of about R12000 and only about R400 was left then suddenly they stopped debiting. January till March they kept quiet, April I received a call saying I have skipped the payments and I asked what happened to the debit order, I was told that is still active then I ask why didn't they continue debiting? I was told that it will be investigated and in meantime I just need to pay R550 and all other arrears will be stopped and removed as soon as there is an outcome of my debit order. I did pay that amount and suddenly I started getting calls from MBD saying my account was handed over. All I want is a recorded call of 2 April 2019 where we had an agreement and stop getting calls saying I owe RCS because I paid them.