I beg to differ.. My dad hasn't been a part of my life for 2 years and showed no interest in trying (much like how OP's dad sounds). So at my graduation this year he wasn't invited. I was surrounded by family who loved and cared for me :) I have no regrets

The OP was the one to reach out - I'd call that trying to be the bigger person. OP, every family dynamic is different; if your dad is that cold towards you, maybe he doesn't deserve to be at your big day. If you really want him there, you could try and get another family member to act as go-between. Whatever works for you.

Yeah that was incredibly rude. At least OP doesn't need to worry about some rude guy at his grad. I do feel bad for OP though.

Imagine if it really was a wrong number..

That's right, even though your parents are "supposed" to be the main people who bring you up and provide care and love, it's not always the case. There are always other people though that have been there in your life. Invite them without a thought. But for your dad, don't try too hard to get him to be there.

Honestly, call him back and tell him to fuck off. I know there's gonna be a flood of being thumbed down, but he's an asshole. Seems there's a reason you haven't talked to him in such a long time. Live your life, make the most of it, and let every successful event in your life be a reminder as to why you don't need him.

Mail an invitation

I'd like to think OP double checked the number before posting this. I think it highly unlikely that someone would forget their own parent's number/not have it in their cell phone's contact list.

People do occasionally get their numbers changed...