VPN is something that PS4 can't do on it's own, you've have to VPN via a PC and then bridge the PS4 to the VPN via that PC. Some routers might support the use of a VPN service, I've never really looked into that.
You can also badger the heck out of your ISP about ping times and bad routing and ask them to optimize. They may/may not do anything. However it's possible that they could help the situation if there is some bad routing in their network, bu optimizing it.