Anyone else had poor customer service

To start with, I ordered an excellent quality Samsung z fold 5 recently off back market since all my family have phones from them and have raved on about how good the phones were and the service was.

When I received the phone, the outside appearance was unbelievable, it was amazing! The issue is the Wi-Fi would not work when you went to set it up. This should have been checked before they sent the phone, it took me less than 1 minute to find the issue. I took the phone to a repair shop to get an opinion and they simply said to contact backmarket and send it back for repair under warranty. Having sent it back using the Royal Mail in the UK (this was their return service), the Royal Mail had damaged the phone further, shattering the back glass. Now i am without a phone and backmarket take hours / days to respond to my messages. All i have been told is they are investigating the damage to the transit and have provided me with no updates to the phone or what is going to happen. I spent quite a lot of money and am really displeased with how the situation has been handled so far!

Has anyone else had / heard of similar occurrences?