My son got robbed on his birthday

Today is officially my son's birthday.    We celebrated it yesterday.  He had been saving his money to get himself a nice phone (I can't afford the newer ones right now).  This morning, my son found an iPhone X that was close to his price range on LetGo (much like the Facebook Marketplace). I lent him the difference.

I've *always* gone with him in the past as a back up, but I've been feeling sick today.   He said the user had many high star reviews so and we've done this a few times, so I told him to go for it.  I was sick and went back to sleep.

A few hours later, I get a call, he was very upset and I find out that they robbed him, took his birthday money and also his old phone.  I feel horrible that I didn't come this time...   I'm doing my best to focus purely on what I can do.  As a parent, I feel a great deal of frustration towards the situation but I'm trying not to focus on things I should have done and how disappointed I am in some people.  This has been reported to the police, but he didn't know the license plate number so they don't have much to go off of.

I don't normally do things like this, and I know it's just a phone - but they took everything he had been saving for awhile and robbed him on his birthday.  I'm really glad he's safe, but I'm still so disappointed that I didn't come because it would have been a very, very different story.  They took his money and his old phone.  I'm putting this out there to see if we can recoop some of his losses and get him something.   I am hoping the goodness of the community can help turn his day around, even if everyone tossed in a couple bucks, I know it would help so much.  I'm hoping the kindness of the community can help turn this birthday around.  I really appreciate the consideration.