Baby daddy & broken promises

My baby daddy has been a jerk for the last 2 years to our 2 daughters. Spending no more than 20 minutes with our kids every 2-3 months. Just recently he has ‘promised’ to change, again. He then picked our girls up from school on Friday and promised to be back Saturday to take them to the park, he sent a text message Saturday morning to say he’ll still be taking them to the park, and we did not hear from him or see him for the rest of the weekend. But was told from my niece that he was at the same park she was at (that same Saturday) with his girlfriend and her daughter instead, while our 2 kids waited patiently all day for him to arrive and were upset knowing he has done this to them AGAIN. I then sent him a text, he had 101 excuses already to use knowing I’d soon find out and today I ended up blocking him. Am I wrong for blocking him? If he was a consistent father I wouldn’t mind if one time he changed plans, but when this happens every single time he sees them it breaks my heart to watch my kids so upset and heartbroken by the same man and the same broken promises. I’m so full of mixed emotions right now and have no idea how to fix it since he see’s no problem with his actions and is too immature to understand the damage he is doing.