Fondi T708B tablet returned within guarantee days

Hi all<br> In december we bought a fondi for my little sister as she needed a tablet for school.We were happy with the features and the price and that it came with a warranty and guarantee.I even recommended it to my boyfriend and he still has it.Unfortunately my sisters one had a problem with the ON button and we returned it within the first 7 days.We were told that it had to be sent to the manufacturer which had already closed so they would send it in January,which didn't make sense because the guarantee said if we returned it within the 1st 7 days it would be replaced with another 1.In February we were told that the tablet wasn't repaired.In March we were told it would cost R300 to have it repaired.Yesterday (11 April 2015) we were given some sort of invoice that had extra repairs and would cost around R500.4 months later,we still don't have a Fondi and we don't have our money back.Instead we are being told that the guy that sold it to us (Victor) quit.We really don't understand why we are given this runaround.Can someone please help!