Have sent a message with pc world docket number, it was a fixed price laptop repair.

I first handed in my laptop to a pc world for a tech guys repair on 10th March 2010. It was returned to me on 25th March but didn't work properly so I took it back into the store on 30th March. I have not seen my laptop since! I received a text mid April and went to the store to collect it only to be told it wasn't there. Nobody contacted me so I started calling their "helpline" and was told that the store had sent it back as unfixed and I'd have to wait the standard 10 days before enquiring again, I was also told that there was no way to add any urgency to my repair and that I'd just have to wait. On 4th May I received a card from DPD that they were trying to deliver a package, the laptop was always supposed to be delivered to the store as I am never at home during standard delivery times. DPD would not change the delivery address without a charge. I called tech guys and was told they would sort it so that it was delivered to the store not to my home. This clearly didn't happen as the next 2 days I found calling cards showing that DPD had tried to deliver my laptop to my home address. I called again and was told it would be raised to a "Chasing team" who would contact me within 48 hours. They called to say it would be delivered to the store on Thurs 13th May. They then called that day to say there had been a mix up and it wouldn't be delivered. I hadn't heard any more so I called again on Tuesday 18th May and was again told that their only option was to raise it again to the "Chasing team" who would contact me within 48hours. This hasn't happened! What can I do???? Every time I call I am fobbed off. I have been told several times that I cannot speak to a supervisor or to this "chasing team" directly. Calling again just feels like I would be banging my head off a wall! I don't have a laptop, clearly I paid in advance for the repairs and I don't even know where my laptop is or whether it has even been fixed! Any advice? I have never had to deal with such appalling customer service and wouldn't recommend their service in a million years. I don't think I have ever been this mad or frustrated at anything and I'm not the calmest person at the best of times. Clearly however I want my laptop back, I want my money back and I want to be able to get on with my life!! My laptop contains masses of personal information and I have the feeling they don't even know where it is! Please, please help if you can.