The provider de-activate and re-activate my VPS account. Now everything seems to be OK on control panel (SolusVM), but my IP is not responding, and I cannot access to my server via SSH. He says this is a misconfiguration or firewall settings within the VE blocking external access, and a re-install is needed. How can I access to my server to at least take a backup of my data?
SnapOverflow
If your firewall is not allowing any connections, and you can not get into your server. I'm afraid physical is the only solution.
Ask your provider for a dump of your virtual machine or ask them to shut down your firewall.
You could ask your provider to boot your VM with a livedisk and set up SSH. This way you can still access your data, make a backup, and even change the configuration if you think you have found the culprit.