I want my staff to be fixed as u bought it cash on price

I bought an qalldrop and the same mistake I found wen they delivered and returned the product to be fixed, after one day the returned the product appeared that the had not fixed the error I told the about and when it was returned my mother was alone at the house and they told her to sign of which my mother signed and the dei ee told her that if the is any mistake it can be fixed it has 7 days warrant, only to find that the driver didn't read their slip which says it can only be 7 days warranty if it is appliances