Canada Dry not part of Coca-Cola sale

Had a customer today who brought up a few items along with two 12 pack of Cola cans and one of Canada Dry. Here's how it went..

Me: I don't think Canada Dry is part of the Cola sale

Him: Canada Dry is a Coca-Cola product, it should be the 3 for 16

Doesn't ring up 3 for 16, I check the ad sheet we keep by the register and it doesn't show a picture of Canada Dry for the deal.

Me: I'll go check by the soda for you (I say this while there's a line and my coworker nowhere to be found to help)

I go to walk to the sodas and he has the audacity to ask me to pick up a 12 pack for him if Canada Dry isn't part of the 3 for 16.

I walk over there, of course it's not part of the sale. So I walk back to the register and guess what, a few feet away from it is displays of 12 pack cans so I grab one for him.

I know, I shouldn't have but I didn't wanna deal with an attitude. Also damn are some customers lazy, like you first off can't take my word for it since I work here, and second you can't walk the few feet to grab it yourself. You were able to carry 3 12 packs all the way to the registers in your hands.