Bad service

Hi my name is Neo I've made a purchase of two batteries on bidorbuy from thivha online store after receiving the items I informed the seller that something is wrong with the item and the seller said the item might have fell in transit then he requested that the item be collected by the courier and be sent back to them and he will have the item checked and send me other ones but he never did the two weeks later when I inquire about the items he say there's nothing to return and he is focusing on honest customers and can go report the matter he will deal with it Now my question is does bidorbuy allow their sellers to treat their customers in such a manner please advise or do I need to escalate the matter even more