Double billing

I was a Nashua client moved over to Altech, firstly no invoices were sent to me from December and the debit order was not in place, I received an sms stating that the account will be locked. I called Autopage and they then activated the debit for December January and February which went off on the 18/02/2015. On the 27/02/2015 my account was debited for the same 3 months again. The customer service agent could not assist as she could not see the amounts debited.