There is a 1-800 number in the receipt, which you should call (I bought the CDR with mail-in rebate).
The rebate is from the manufacture, and I thnk it is a kind of scam. They wish you will forget. That's why they make the waiting period very very long. When I called them in March, I was told it was still in processing, and it would take another 3 weeks. I called in April again, and I was told they are going to send out the next day.
Now, I got the cheque (just got it yesterday), after long waiting period and several unanswered/answered calls.
Don't give up, and keep calling them every few days.