Double Deduction Jan 2016

I have been billed double for medical aid and I don't know why. I have called in the call centre this morning (***) and according to them they can't see this double deduction of R3380. I have also called my HR Office as this was done via my work and was told by them that refunds can be done by the Medical Aid direct. the call centre agent advised me that this deduction is for Jan and Feb as I pay in advance which is contradictory as when I joined I was told that I will be paying in arrears. my cover should haved started on the 1st of Jan 2016 and deduction of R1700 should go off on the 27th of Jan 2016 and not R3380. That's the contract i signed when i filled in the application form. now you go and take my money as you please, I want my money back ASAP. I don't owe Medshield anything and I want my refund.