I am going to try to keep this as short as possible, but it may require some exposition.
My DP just got a new job because he hated his last one. I am a stay at home, so I don't have an income (this was something we discussed and he suggested). When he started the job, I asked him to speak to HR or accounts payable about exactly what to expect for the first paycheque as I know sometimes this can be a bit wonky as they are adding new employees into the system. Because I am not working, money is a little tight and I just wanted to be prepared for exactly when we could expect money coming in.
A bit of background: my DP has a history of making assumptions and getting it wrong. For example, I asked him about something to do with his student loan. When I followed up with him about it, he very clearly explained about how his work would arrange everything, essentially. I looked into it later (I can't remember why) and found out that what he told me was completely wrong. When I confronted him about it, he said that he "thought" that was how it was done. This is only one of many examples, most less serious than this one.
This was the same. He was meant to get paid today. Cue this morning and no new money has gone into our account. I asked what's happened and he tells me that he's not sure and that the guy he sits next to swore that this was payday. Eyes narrowing, I asked him what HR or accounts payable had told him. Turns out, he didn't ask them. I asked what his manager had said. Turns out, he didn't ask her either. Nope. Even though I specifically asked him to talk to someone in charge, he thought that it was just as good to ask some random colleague and just assume that guy would know what a new hire in a new team could expect.
So obviously I am frustrated. I am trying to keep my cool, but this is more a "straw that broke the camels back" kind of thing. I have spoken to him before about his habit of doing this, so it's not like he is unaware. When I asked if he understood my frustration he said "Of course I do. We're broke." As if that's the problem I have with this situation.
He thinks I am over reacting because it was just a mistake. I think I am being completely reasonable because this specific kind of mistake happens regularly and we've spoken about it in the past. I am angry that he dismissed me and essentially lied to me. So, am I being unreasonable? Should I just shrug and say "mistakes happen" and let it go?