REPAIR COSTS ON PRODUCT STILL UNDER WARRANTY

Power tools >RYOBI took it in to the MICA store(Where I bought it) in Benoni Elston Avenue in OCT/NOV 2015 for repairs, they repaired the faulty charger with no cost, December 2015 it broke again after using it ONCE it stopped charging again. I took it back to Benoni Mica and now they want to charge me R790.00 for repairs while the 2 YEAR warranty has not expired it is not even 1year old the first time, How can they charge me for repairs on goods that is still under warranty!! I am not going to pay the repair cost as it is not my fault but a faulty product I want to be refunded in Full so I can Buy another product this is ridiculous.<br> Please contact me ASAP I know I will no longer be purchasing ANY RYOBI products or supporting Mica Benoni again!<br>