So this happened a few nights ago. I was actually having an amazingly good shift until two of my regulars showed up. Now the first one is a rather rude lady that has to have her store card looked up every time and will not let us start ringing her up until it's found by a clerk. It's usually a very awkward transaction, just standing here waiting for a good 3-4 minutes. But that's not what this story is about. Oh no, Number 2 is where things got technical.

The second regular that showed up immediately after #1 is a local businessman. He's normally very kind on the off chance he doesn't have his cellphone glued to his ear. Literally, it's practically implanted most of the time. So I've learned to usually get him through quickly and efficiently with little talk as possible. He tends to ignore anything i say anyway, as evidenced by the fact that i usually have to ask for his store card 2-3 times. Anyway, he shows up with his usual order, no cellphone this time, and i greet him with my usual line.

Me: Evening <honorific>, Do you have your <insert store name card>?

I take his store card, process his debit card and hand him his receipt. I even bagged the order for him. At no point in this has he ever shown any anger or annoyance with me. So imagine my surprise when he looks me dead in the eye and says:

Regular 2: You have got to be the worst Cashier I've ever met. You have never greeted me, you never say thank you, you look miserable. In the 20 years I've been shopping here i have never had such terrible service from anyone but you.

I just stood there in shock and then actual rage. I've been dressed down and threatened before, but this just took the cake. All i could think of was " maybe if you'd get of your Cell, you'd have heard me every time I've spoken to you for the past 3 years". Sadly i didn't have the forethought to tell him this. All i could do is tell him, as he walked out, that i had greeted him. I'm still rather confused as to how this all came about considering i've talked to him at length before about his business's. So there was no track record of any malice until the incident.

TL;DR: Cellphones make you deaf until they get taken away.
Edit:formatting