Currys PC World

I bought a laptop recently in October, I received a month trial of product support and was told to cancel if I didn’t want to continue with the agreement. 2 months pass and it slipps my mind. I check my bank statement and I see only one payment of £7.99 leave my account for product support. I immediately rang the support number and cancelled my agreement with the intention of receiving a refund for the previous payment taken from me... this doesn’t happen. I check my bank again to see only 3 days later another payment of £7.99 taken from my account. This is not right and unfair as I explicitly cancelled my agreement on the phone.