Tool box aside, I went to a ratty El Cajon CA store on memorial day to use the 25% off coupon on that Chief impact gun and they didn't even look at it or scan it. Just take off the 25% and get the hell out of here mister.
This may be toward the employees of El Cajon in general (the **** of San Diego), but I asked if I could grab a tool box using the same coupon. Reply: "I already rang you up, I don't care what in the hell you do but I just gotta ring you up again". I had the kids with me so it wasn't something any of them needed to deal with, so I just left. It'd only be better if she was smoking a Lucky and swigging some Hamm's beer at the register.
So in short, I suppose stores are hit and miss. Coupons don't matter, Coupons do matter, and sometimes customers in general are a bother.