Oneday only is a **** 😡

I bought a grass cutter machine on the 11 April the machine was delivered on the 17 Thursday on the very same day I noticed that the machine is not working I logged a request for collection of the machine and a full refund because I needed the machine urgently. It took them another week to collect the machine not they are saying the is nothing wrong with the machine they want to send the same machine that I said it's not working they are refusing to give me my refund back. At first they said they are communicating with the supplier for the refund not they say they can't refund because it over 7 days. Oneday only is a **** they don't put customers first in terms of service it almost a month of back and forth of email 😡😡😡