Anybody having problems with RMA process? Help needed!

First of all I don't want to come out as pain in the a** customer but here it goes:
I bought my 32GB Playbook from Carphone Warehouse just after Christmas - and after receiving the unit I noticed straight away that it had a dead pixel straight in the middle of the screen. Cut the long story short - CW people told me it might be better to deal with RIM since they don't have any in stock and couldn't guarantee that they will exchange it under 28 days since the date of the purchase - later it's the same repair process as with RIM. So I did contact RIM send them the pictures of dead pixel - got the advanced exchange approved and hoped for the best.
- 1st process went quite fast but the unit I received had a raised screen in top left corner and there was quite a nasty light bleed around that region - unit seemed to be an refubrished model (although the RIM representative on the phone mentioned that it will be exchanged for a new unit since I contacted them around a week after the purchase). Was advised to send the advanced exchange model back and keep the first one
- 2nd process took them more than 2 weeks and it seems that I received exactly same unit that I have sent back - similarly raised screen in one corner. light bleeding through and additionally a substantial buldge on the back (which I might not have noticed in the previous unit). Unfortunately for me I didn't write down the serial number of the first RMA so can't be sure - but similarity of faults is suspicious.

Awaiting for their reply now - but what would you advise me to do? Honestly I am more happy with my initial unit (one with dead pixel) since its faults are less visible and affect me less when using the playbook. And it seems that they are sending me units which shouldn't pass a quick quality control - you notice those things in first minutes spent with the device. Really frustrated now - so would appreciate advice - I really like the Playbook - it's a great device but all this hustle and problems with simple exchange are just depressing. :(

I had the same problem with a different manufacturer. The first time they sent back my broken unit and the second time sent me a different model. Try again. You have nothing to lose but a little time.

I also would try again. If you really get no satisfaction, if you used a credit card, you might dispute the purchase and return it to the retailer (I don't know time limits on such disputes).

Good luck.