Theft of my hard earned money

I just realised that Sage Pay has been debiting money from my account since December 2016 under the reference Mutual Direct ***0 Sage. I do not know who these people are and what they are selling. Never gave permission to debit my account. In fact I do not have debit orders as I pay all my transactions on EFT because I don't want people accessing my account. So they must not even come with a story that I entered into a contract to have my account debited. I DO NOT GIVE OUT MY BANKING DETAILS. I also DO NOT BUY ANYTHING TELEPHONICALLY or on the INTERNET. My bank is only able to refund me for 2 months worth of debits. So Sage Pay, please pay back my money. I also need proof where I consented to my money being debited.