I understood the problems you had with AAP online, that has nothing with personal service you received at B&M store. Most counter person just do exactly what was told, if they do anything else they may get fired.
This story may not be the exact same thing, but it is close: I got an email from O'Reilly for a coupon to but something for $0.99 with regular price of $4.99. I went to a local store with the printed coupon, the counter person could not enter that part for 99 cents, the computer showed $4.99. He first told me that the part was $4.99 plus tax and coupon was invalid, I asked him to get the manager to override the computer so that I would paid 99 cents plus tax.
He finally went to back room to get the manager and everything solved, I got my part for 99 cents and he didn't into trouble.
I don't expect much from part counter person, anything that is not to my satisfaction is usually up from corporate level, their policy is usually the root of the problem.