Power surges do not excuse warranty and guarantees

Helicopter, I made purchase of a Television set at Picknpay East rand mall(now east point) on the 18th of Novemeber 2017. Last year I took the tv(hisense 49"[***]) in for a check up because it would not switch on and promptly after having dropped the tv off I received a call from the technician saying the tv had went through power surge and that I should contact the store to collect it. So I did go and collect but before I took the tv into my possession they explained to me that it would not be fixed, having asked why they said they do not fix power surges and that I would be charged to fix it. Why am I paying when it is still under warranty and guarantee