Check out the dispute policy of your credit card company if you bought the items with a credit card.
In general I believe it is a true statement that if the merchant advertises a product as having X features, X rebate, X warranty, etc. and the product that is delivered doesn't match the advertised deal / rebate / features, or if they don't send the product at all, or whatever and charge your card you can dispute the charges because the transaction wasn't honored in that they didn't deliver everything according to their claims about the product and the overall deal concerning it.
At that point the credit card company has to investigate it with the merchant and also with the rebate company if a rebate was advertised as being available. If they can't prove that they honored every bit of the advertised deal and delivered everything promised (including the advertised rebate), the credit card company can and will refund your money for the transaction and the merchant doesn't get to charge you for something that isn't delivered as advertised in full including the promotions / rebates / discount / warranty / whatever.
If you have photo copies of the rebate stuff you sent in and any other possible relevant material like a screen shot of the product advertisement page advertising the rebate promotion then it will be pretty easy for you to dispute that you should've gotten something out of the transaction that you were promised that they didn't deliver in good faith / competence. Since you got a notification from the rebate company that they DID receive your submission they can't deny that they received it at all, so the only thing they could claim is that you didn't submit it properly, but given their bad reputation for trying to scam people they owe money to and their general reputation for incompetent processing of many rebates it will not be difficult to prevail in the dispute unless they have very strong and visible proof that you aren't owed the rebate. The CC company will definitely do everything up to demanding the original copies of the rebate stuff the rebate processor received from you, and if they don't submit it or there's any doubt that they conveniently 'lost' part of the submission, you'll win.
IMHO it is only by making it an annoyance for the credit card companies and the merchants that participate in the rebate scam that the practice of these dishonest rebates will end. If more people either sued them or disputed the transaction with the CC company it'd end up costing them more to try to scam consumers than just playing fair or just not doing rebates at all and having actual SALES with no strings attached.
EDIT: PS that's why I usually do stuff like print the receipt/invoice photocopy on the SAME piece of paper as the rebate form, and when I attach anything like the UPC I'll STAPLE and TAPE it numerous times and then mark around the edge "UPC ATTACHED RIGHT HERE" in ink, etc. so basically they'd have to physically destroy your rebate submission to "lose" any part of it, and it'd be totally obvious if they did detach anything. I take a picture / scan of the assembled bits, and send it in. There can never be any question at that point that it was all there together and filled out properly, and once they send you an email / post card saying they received the submission they can't claim they didn't get it.
At that point if they give you any problem you've got more than enough convincing evidence to dispute it to the CC company or sue or whatever you need to do.
I won't play their games with their lying customer disservice representatives who will promise you they'll take care of it and then do nothing after hours on hold / getting screwed around etc.
Originally posted by: terpsy
Personally, I will NEVER buy another Diamond Product again.
The two times I had mailed in for rebates, BOTH got Denied.
And I could not find a working number to contact.
I got the email that something was missing and they would be denying my rebate.
I HATE companies like that, and always tell people buy anything but a DIAMOND product, they will screw you.