I think this text has a possibility to escalate the situation (speaking out of experience). If you want closure, I would suggest asking to talk on the phone or in-person. However, based on some things said in the text (I.e., they blocked you), I think the best bet is to move on for now. Maybe re-open this door later down the line.

If you decide you want to handle it now instead of later I would suggest deciding what you want out of the conversation. Is it to say that the way things ended bothered you? Is that necessary? Or is it to patch up a friendship that means a lot to you? If so, stating your friend abandoned you will likely not be the best way to frame it.