Boodle loans are charing extra fees cause they fail to response in time

I paid my account as the amount Due which was send per email to me. I've emailed proof through and got a response thank you. This was on the 3rd of April 2020. On the 6th of April I received an email that I am overdue with a certain amount. I contacted them via email requesting where this amount is comming from as I paid the amount from the invoice that was send to me on the 3rd of April stating amount due. Then I received an email back they are attending to my email will response in due course. On the 9th of April I received another email saying I need to pay the outstanding amount which I decided ok let me just pay it and get it over with. HAH. I Forward the proof of payment and within MINUTES suddenly I get another invoice saying I need to pay another amount. But they can't reply on my first important email explaining where the additional amount comes from but when I need to pay more they can replying IMMEDIATELY. This company is a *****. I refuse the pay the add on fees as I paid what I should. I done my part to contact them and its their lack of response or not feeling to care about their clients. I am finding out how to report a company like them to the consumer act. All contact I prefer on email so All proof is there what and who said what. They just want to ***** from people with the little they have.