Swapzone & Changelly should've contacted him to help but they don't want to accept it's their fault. Changelly's given the address so it shouldn't be hard to give the funds back.
Most exchanges can handle mistakes like this. They can retrieve the funds and if they will have to do it, they can without any doubt. But with what I've seen with exchanges (not instant) they are charging fees and anticipates that there will be users that will create a mistake of sending it to the wrong network. But in your case, it's different. Whether they believe you did a mistake or not based on what you're telling us, the funds should be intact on that provided address which means if they own it, they have it.
That's the problem, both don't want to accept that it's their fault after all. They have left OP hanging and this is hard to be honest, you've used them trusting that your funds will be on the right platform for the swap but it didn't happen. We're all aware that these platforms shouldn't be trusted but we cannot help OP and the others that haven't come across those scam accusation threads for how ugly their services are.