I had a similar problem with car phone warehouse. They are scum in my opionion. they had my phone 6 or 7 times for repair. The phone came back with the same fault every time. I truely believe they didn't even try to fix it.
Every time I complained, They blamed the manufacturer (panasonic). So I phoned up Panasonic and spent 10 minutes shouting at them before they told me that they had never had the phone for repair. I phoned CPW (using the number on the repair recipt), they confirmed that the phone had never been to Panasonic for repair and I had been lied to in store.
I will never buy from Carephone Warehouse again!!!!! Their customer service is as bad as it can possible get.
I sent the phone directly to Panasonic, they repaired it, it lasted a couple of months before it broke. Next they offered me a replacement, The replacement then broke too. Panasonic then offered me a full refund or a completely free upgrade (the phone is nine months old at this stage). I took the money £180 (i got the phone oncontract so I didn't directly pay anything for it).
If the phone comes back broken again, I would go directly to the manufacturer with it. It shouldn't cost you anything.
Avoid Carphone Warhouse.
(I wrote a complaint to CPW, they appologised and offered me a £30 gift voucher. I said "shove it, I don't want anything from Carphone Warhouse again, even if it is free")