Partner lying & ignoring messages

My boyfriend didn’t text me back all day which is fine - people are busy.

But, he is actually supposed to be in the middle of making things up to me after ignoring me for an entire day that we were supposed to go out for my birthday a few weeks ago. He was too busy getting drunk with his brother and then he continued ignore me for two whole days (including my actual birthday - I didn’t even get a “happy birthday”) and then didn’t think he did anything wrong????? He always chooses to disregard plans with me for his brother.

Anyway, it got to 8pm and I messaged again asking what he was doing tonight. He finally messaged me saying he might go to the local bar with his brother. I said I too was maybe going to the local bar.

He again actively ignored my messages so at 10pm I said well did you go out...? To which he said at 11pm “no I’m just sitting in my brothers”. I then messaged him again saying “ what you guys doing? are you going out? I’m just at the bar with my friends” Which he again ignored. I messaged him half an hour later saying “you’ve been really off today” and he again ignored it.

At midnight I seen him walk down from the upstairs of the bar I was in and leave!!!!!! So I stormed after him and he looked like a dear in the headlights. I said “sitting in your brothers yeh?? What is going on?” And again he has the cheek to say I was craZy and the one with the problem! When he completely lied to me! I said “I’ve messaged you, have you been ignoring on purpose?” And he didn’t say anything so I said show me the home screen of your phone? And he refused. So he’s clearly purposely ignored my messages. Whether I was in the bar or not, as how long term girlfriend I expect him to check in now and then to let me know what he’s up to especially when if I politely ask! He doesn’t think what he’s done is strange or sneaky at all!!!!

He leaves on Monday for a few weeks, and after this convo he stormed off from me saying I should make plans with my friends tomorrow as he won’t be seeing me! Rude when he’s in the wrong. I said “cool. Maybe actually text me back when you decide if you’re going to make me a priority in your life for once”.

I haven’t messaged him since as I don’t know what to say or how to make him see how messed up this behaviour is. I was away on holiday last week and he was messaging me constantly and getting bothered if I didn’t reply within 10minutes so it’s so messed up that he would now be the opposite.

Honestly baffled I physically caught him lying to me. I don’t think he would have text me or let me know he went to the bar at all if I didn’t see him.

Please help me.