mixtelematics accounts department trying to **** me

I have been contact by their debt collecting company saying that i owe them money of which its not true because i have been paying them via debit order. I called their accounts department to explain to them that i do not owe them and they just place me on hold for more than 12 minutes and then they cut the call. I even tried to send them my bank statement to prove that they have been debiting my account every month, but they still insist that i owe them. Their accounts department are *********** they cant even read a simple bank statement.