I can just about guarantee that the person did not do something just to aggravate you.
The universe did not conspire to cost you a few extra minutes of time. If the universe did conspire to cost you some extra minutes, it may have been so that you didn't get into an accident or have something else disastrous befall you.
The technology didn't decide that it was time to make you pay for not liking technology (or liking it too much).
It's not a conspiracy to waste your precious time. Everyone's time is precious to them.
Think about it from the other person's perspective for a moment. What if you were at work and some stranger came in and spouted off at you for something that was out of your control? Likely you would be royally ticked off. Yet we expect folks in a service capacity (cashiers, servers) to take whatever crap we dish out just because we feel slighted. Grow up. If it takes an extra minute or three to get checked out at the store because of something beyond the control of the cashier, then make small talk with them. You might be surprised how much a little civil interaction can do for you and for those around you.