I am in a similar situation to you. I suggest that you write to RPT to tell them you are no longer comfortable with obtaining Amazon product reviews or Amazon seller feedback through a rebate service like RPT. (fyi. Amazon see this as incentivising reviews which crosses the line of what is acceptable within Amazon TOS and some members have received warnings from Amazon on this).
Ask RPT what options are available to you. They can probably organize for the reviews to be posted outside of Amazon, e.g. facebook or Twitter, or perhaps they can refund you for the reviews part of their service. If people are already ordering the product then it may be difficult to stop the actual promotion but you should be able to stop any reviews being posted on Amazon.