Awful treatment

Avis handed over my account to attorneys without even informing me and when I called they told me they are not debt collector whereby they send constant reminders to their clients to make payment. I had to pay the account that was handed over to attorneys without my knowledge, I finished paying them last month on the 20th, we are approaching the 20th again but they haven't sent me my paid up later. They were so quick to hand me over but they are pulling their legs to provide me with a confirmation that I have fully paid them.