Christmas Shoppers: If it's called Boxing Day am I allowed to punch customers?

Ah Boxing Day, here to mark yet another year where I have ‘Ruined the kid’s Christmas!’ and triggered divorce proceedings for families everywhere! Oh the unrivalled joy of working in a shop the day after Christmas.
In an ideal world, I would spend Boxing Day as I always have, stuck to the sofa watching crap television just because it’s on and building a pile of empty Quality Street wrappers in the process. But instead I find myself returning people’s clearly unwanted gifts for reasons no more imaginative than ‘My dog ate it’ and nodding and smiling at people that say ‘Awh I bet you just want to be sat at home don’t you love?’ Yes, thank you for the sympathy Captain Obvious, I do, and if you feel that sorry for me, go home and put last night’s pyjamas back on like a normal person so I don’t have to pretend I like you.
I genuinely believe that simple manners make the world go round. But it turns out Christmas ‘tis the season to be an ignorant... well... arsehole... fa la la lala, la la la la. I mean honestly, is it so difficult to respond when a person behind a counter says ‘hello’? I don’t earn commission; I’m not trying to sweeten you up. I can’t stand handing a carrier bag over to someone who I know will not even bother to look at me as though I’m some lower life form (FYI: I’m the one in the uniform, you’re the one in the tracksuit. Do the math.). So much so I’ve decided to be less discreet about how much this makes my blood boil, by rolling my eyes until stuck in the direction of the next customer in line as a warning to them that I will purposely put the wrong thing in their bag if they don’t so much as say a 'thank you'.
I even had a customer yesterday who, when told that the product he wanted had sold out, stamped his feet like a child and came out with this little Christmas cracker, ‘Tsh, you’d have thought you would have got some in for Christmas.’ Well, yes sir we did, that’s why we sold them... at Christmas. Maybe what this customer should have asked himself is why the hell didn’t he get his lazy self up on Christmas Eve and buy it then like the rest of the world? You have to laugh, otherwise you’d end up drowning in your own tears of frustration at just how unreasonable and plain stupid some people can be.
Another thing I hate about Boxing Day shoppers are infallible customers and their children from whom the sun shines. A lady came in yesterday and asked to return a ‘faulty’ game that had left her son very upset when it stopped working mid game on Christmas morning. Poor lad. Yet when I checked the disc I saw it had quite a hefty mark on it, something that I think Mr. Activision would have picked up on during a quality check. When I approached her with the EXACT reason why this had happened (I was polite about it but really what I meant was ‘Your son is a bit of a douche and clumsiness caused the mishap.'), she proceeded with that awful snotty tone regular people put on to exert authority in these situations and instead suggested it was my fault asking ‘But how do you know? How do you know that’s what happened?’ Well because Ma’am, I work here and you don’t.
I mean honestly, if your eight year old kid is stood next to you whilst you argue the toss and ask a sales assistant ‘Why are you selling faulty goods to children?’ (To which I feel like screaming at them: WHAT EIGHT YEAR OLD NEEDS AN IPOD TOUCH?! YOU EVIL PARENT, DEPRIVING YOUR LITTLE GIRL OF GOOD OLD DREAM PHONE AND THE THRILL OF MONOPOLY!) you might as well just tell them there and then that Santa clearly doesn’t exist... Unless I look like an elf?
Thank god it’s all coming to an end. Don’t get me wrong, I LOVE Christmas, I would go as far as to say I pretty much live for Christmas, wishing it could be Christmas every day. And it's really not every shopper, some people are genuinely really grateful for my help but every year these people come in like mini Grinch’s desperate for someone to blame for their disastrous Christmases. I might go all therapy-ish on them next year and ask them, (Cue patronising tone) ‘Is a gift REALLY more important than family at Christmas?’ Anyway, time to brave the January sales and I’m sure be blamed a multitude of times for not having a product to fill a shopper’s display case. There’s a reason it’s called a display case... It’s to display. I’ve decided I’m going to be stubborn, go crazy and not live by the shop monkey book and really drive home the point:  The customer sure as hell isn’t always right. Merry Christmas.
Love L x