No, the guy is seriously annoying here, even if it’s a misunderstanding. What do you mean you set a date and time, then cancel it at the last second, not once, but twice? I can understand the first excuse, that he had to fill in for a sick coworker, but for the second time too? If he truly valued their promise, he would’ve told his manager that he already had plans and couldn’t fill in again. You can’t force a part-timer to work, and what kind of shop shuts down just because they’re one person short?
I seriously hate how this played out. I can already see it going down the route where he gets a raise for working extra hours so he can buy her a present, but what’s even the point, when he’s already let her down twice? It’s just plain rude, not only in a relationship setting but with anyone you make plans with. It shows you don’t keep your word, you can’t fulfill basic promises, and therefore you can’t be trusted.