Why do CM's get mad when calling about a PIN?

[cheerful chickadee]

We called and while our CM was not overtly rude he was very short with my DH once he realized we were only calling to see if we had any PIN's attached to our name. He replied "no discounts are showing up by your name sir" my DH then asked if he would check my name just in case.....the CM cut him off and said "make that....no PIN's for anyone in the guestbook, sir" and said have a magical day and the call was over. It was a sudden answer so not sure how they even "check" for codes. We probably won't call again unless we actually receive an e-mail or postcard.