UNAUTHORISED DEBIT AND *****

SAGE PAY has being debiting 99.00 for the past 2months for the company by the name of SA Unathi, I do not know them,I do not know off them and I have never issued any rights or sidned anything for them to *****l my money every month. I tried calling Sage Pay and they gave me the following numbers *** or *** that are just ringing with no answer, what I do not understand is why Sage PAY is making Unathi problem my problem when they are actually the ones debiting my bank account illigally? Please help Reference numbers changes every month