Actually the services like Haphost stopped the resgistration due to lack of IPv4, so you must wait until the registration is open.
But there's FreeVPS however the disadvantage that website is a forum and you need to be active everyday to keep your VPS otherwise they will suspend your VPS due to inactivity.
Otherwise, you must host your server by CS2D Dedicated Server (yea, this won't satisfy your problem and is not related to your thread but you can't simple get a VPS for free, so you must pay for it).
I agree with @ GeoB99.
Also, there is a website that host a free VPS, but i don't know how.
Maybe, you must make an application there to get it.
Anyway, the website is: 5jelly.com.
@ THEMUD: I won't recommended 5jelly because that website is purely fake and scam.
nop , 5jelly is pretty good on hosting , but to get a free vps u need to complete alot of surveys , i got an VPS with 1GB ram for free from there but theres no OS installed in , i also got a free website from it .
People wont use money on hosting , so why your searching for it , visit the nearest bank and pay them to add some money to your PayPal account , now no one would give free vps cut its expensive and everyone want it , so haphost and vps.me don't give free VPS any more cuz they are out of it .