Rear noise

:banghead: I hear a lot of Tahoe owners complain about the clunk in the rearend. I have had the spider gears replaced, slines greased, U-joints replaced, (transfer case)?? oil changed. Noise still there. Now they are bending the leaf springs to correct the ride highth. I've only had this Tahoe for 2 months and thinking about asking for my money back. It is under a 99 day warrenty and they are about sick to death of seeing my face walk through the door.
HELP!!!!! What should I do with 2000 Tahoe with 30K mile and heated leather seats AAAAAAHHHHHHHH but I love it. I just hate the annoying "clunk"