Refund Rejected

Last night my car got stuck so I ask a friend to accompany me to Engen to purchase a new battery with the old one in hand the the exchanged the battery and gave me a new one , this new battery was above the AH capacity of my old one. I installed it and right after my head lights blew . I return the battery request a refund and I was refused a refund from the merchant VIVO Service station in Polokwane Grobler street.