******* masquerading as online store

I completed a "survey" on facebook advertising a shell petrol card with pre-loaded funds for R60. I made payment just to realise I am now subscribed to a site called The save magnet. I immediately went to the cancellation option on their site. I completed this form twice. Never received a cancellation confirmation. Today I was charged again. When I started querying I was told my profile is still active. I am now cancelled but they refuse to give my money back.