Misled

I was contacted by a sales agent about a tablet who said once I receive it via courier I could open it up and have a look at it, even switch it on and see how it works to decide if I like it. I then have 5 days in which to send it back if I don't want it! I asked if there are any costs involved if I wanna return it and he said NO! It arrived, I opened the box and was disappointed. I contacted the call centre the same day to arrange the return, then was told I now owed 30% of the deal PLUS R99 service fee. Asked to speak to manager but was unavailable, agent sent request for call audit expected reply 48hrs later, had to send email to request a response. 1 week later got a call NOT in my favour, requested the recorded call which will take another 36hrs BUT 30% pmnt is due Mon or else I'm bound to a 2 year contract! I feel totally misled by the sales agent and now being charged over R500 for NOTHING!!!