refunds for an unknown policy

I have seen my payslip and I called old mutual head offices to ask about a policy that is debiting an amount of R303 from my salary since July, of which I know nothing about. They told me to go to the nearest branch with an affidavit, a bank statement and a copy of an id. I did as I was told but to my surprise I was told at the branch that I won't be getting any refunds, I tried to query but that was just it. I never authorized anything from old mutual and I don't even have any kind of policy with them. Please help me get my money back, the reference they gave me is CEB ********** 986. The one on my payslip is ********** 144666B4