********** debit for false advertising

So on Sunday I logged on to the Showmax website and noted that they offer a free trail for 14 days.I then subscribed to this option but then decided to upgrade as the amount advertised was R225.00.To my surprise they immediately debited R449.00 from my bank account.I was so upset that I cancelled the service immediately the same day.When I queried this on their facebook page I was given a run around and was told that I signed up for the pro package.The person asked me for the proof of payment and 2 days later I'm being told there's no refund due because I signed up R449.00 How to take a full monthly instalment for something that I cancelled literally within a few hours of activation.They refuse to give my money back despite me sending them screenshots of their false advertising on their website.******** for real.