Did you receive the apology email from S&W? We're sorry it's taking so long to send out the checks yada yada...
I ended up calling them when I received a letter dated May 31st but postmarked June 26th stating I had entered an invalid serial number. S&W transferred me to MPS (company handling the rebate) and it went to voicemail stating they would callback next business day.
Ended up going back to S&W website to "chat" with a customer service agent, explained situation and said that I had purchased 3 firearms and was curious as to which one was invalid...expressed my disillusionment with entire process and she provided a different direct phone number and offered to stay on line as I called.
In the end, they apologized, stated that two of the checks had already been mailed out and the third would be mailed out shortly now that the "issue had been resolved."
I purchased these pistols the first week of April so in the end it will have taken closer to 16 weeks. But hey, "The checks in the mail"