Stupid ex vent!

I have a 5 year old daughter with my ex and today he was supposed to pick her up from school because I have class until 245. Well I called him and he hadn't gotten her yet and on top of that he lied and said he was on his way when I could tell he was just waking up and no other sounds were there so he wasn't even driving!! Her teacher called me to see what was going on I explained to her that her dad was supposed to pick her up today because I just started school and she is aware that her dad isn't the most reliable person but still I am beyond embarrassed and angry! How do you accidentally fall back asleep and not pick up your child from school! I feel like her teacher must think I'm an awful parent! 😡