Harassment!

I have made arrangements with you with regards to my Woolworths Visa Account. a debit order goes off my account every month on the first. In December a debit order went off on 01/12/17 great! no problem. Then without prior arrangement on the 20/12/17 another went off, so now I have been double debited! Still no problem, I think great, no need to worry about payment in January. 04/01/18 message from Mooney Ford to say my debit order has not gone off my account, funny since there was money, and no debit order has bounced back? but double debit order in December means I am not in areas. FABULOUS! Call MONEY Ford and rectify the problem, my next debit order will be 01/02/18. But no, since then I have received 3 mails and 2 messages threatening me with legal action. Not to mention, I have requested on numerous occasions a statement of all payments I have made and remaining amount owed, and absolutely not a peep from anyone, for all I know I have paid off what I owe and am lining the attorneys pockets! Regards ANGRY!