sears rebate switcheroo

rebate said "free installation" for a dishwasher that i bought. When came time to get the rebate, they wouldnt give me the full install-cost because apparently my purchase didnt qualify. The shifty thing was that they referred to a rebate offer # that was not the same offer # that i was given during my purchase. My rebate offer was still valid but somehow these other rebate offers also kicked in with additional restrictions that caused all the hassle. In the end i got $100 less than what i expected for the rebate amount.