Appauling treatment of clients

I am shocked as I write this, I received a letter of demand from your attorneys instructing me to secure an amount owing which I have never been notified of. You debit my account monthly and am surprised why I would have any amounts owing. worse why was I never contacted by your collections team before having my account handed over to your attorneys. How is it that you have never bothered to contact me about this and what led to this drastic step, where have I refused to pay any amounts owed? This is very disappointing and so unnecessary, so you ready to blacklist me over an amount you've never even bothered to notify me of owing, what kind of service is this? can you prove to me when you attempted to contact me and failed, send me anything that proves you notified me of any amounts owing and tell me what and why am I owing??