UMG, United Marketing Group Billing checking acount $49.95 without authorization Plainfield Illinois

I have had a $49.95 fee being charged to our business account for almost 9 years; it was always assumed that this was a fee for tech support through our credit card processing company, Merchant Services. Recently after changing c/c processors it was found that this $49.95 fee was not coming from Merchant Services but rather a company known as UMG, United Marketing Group. After long conversations with UMG they are claiming that they will refund us 12 months of this fee ($49.95 @ 12 months = $599.40) Asked how this fee was authorized, they claim over the phone? I asked who/how they obtained a checking account number/routing number over the phone. There response was that it would have to be investigated, on there end, at the "corporate level”. She said they would get back to me. After only a short time researching this company this is a common theme for them. What can be done?