I can't say this enough:
When dealing with RPs, save your confirmation emails from the vendor until you've received your points!
I had been burned on a few purchases made during my earlier days doing RPs. Now I keep the confirmation emails in my offline file cabinet until I've got my points. I know this won't help those of you who have already lost points because of poor tracking by the RPs, but maybe it will help someone who is just starting out. Pumba526, if you don't get credit for your purchase in 20 business days, email membercare and attach a copy of the confirmation email. You should get your points.
Personally, I think RPs purposefully do not credit a certain percentage of purchases in the hopes that the members don't realize that they never got credited. I cannot believe that their tracking software is THAT bad.