dtrpg stopped the cashback months ago or last year.
RPGNow stopped their cashback program after they did the 10% cashback special (I think that was in June or May).
Both times the programs were ended I only found out after I noticed I didn't get any credit after orders and emailed their customer service to ask about the situation. I never saw a notice on either site or got a general email announcing the end of the programs, only responses from customer service explaining the situations in response to my specific questions.