What would you do?

I adopted a shelter dog with an ex 3 years ago. The dog lived with me for about a year until my Dad got tired of the shedding and asked me to give the dog to my ex. We broke up a couple of months after I gave the dog to him. At first we agreed that I could see the dog every two weeks then it became every month and then it became every 3 months (I would ask to see him but schedules wouldn’t work). Now he barely even responds to my messages or takes hours/days to reply and even then still tells me he’s too busy to give me the dog. At one point he blocked me when he started dating a new girl so for the two months they dated I couldn’t even reach out. I only found out because when they broke up he told me she made him do that. Overall, he’s being immature and lacking communication. Some people tell me it’s not fair for me to lose a dog I helped raise and others tell me I should leave them be and be happy he has a home. It pains to never see the dog again and me and my ex don’t even have issues but we just aren’t close. I don’t know what to do. Do I confront my ex on his behavior? Do I just give the dog up? Do I propose a new way of handling things? I have never been in this situation and don’t want handle things poorly.

hartfire

The owner of the dog has all the rights, so there's really nothing much you can do about it.

Just some ideas to contemplate.
If you're still living with your Dad, ask him if he would accept to having a dog that doesn't shed.
Poodle and Schnauzers don't shed; their hair grows continuously. This means they need lots of regular grooming, and full clipping in the warmer months.

Or consider leaving home and living independently so you can have a dog (or two).

Or consider volunteering a few hours a week at a dog or animal adoption centre.

I can't have a dog because it would chase our wild wallabies, and I don't like having to tie up a dog or keep it in a small yard. Instead, when out, I ask owners if they'll let me pet or play with their dog. Most owners are happy to say yes. (Alas, not during this COVID shutdown.)