Perform a whois your vps IP. Contact the company which owns that IP. Pretend to be bewildered and you may get some info. This company you are calling likely manages the network and physical hardware for your "host". I have worked with clients who had hosting service outsourced to other network providers (through middleman-osts), only to find out that the middleman host did not make their server payment, and the server was taken offline. If you cannot reach a service provider and cannot reach the service you pay for, connect the dots, and it may be time to jump ship.
How to spot a hosting reseller:
a. ping "web-hosting-company".com. Search that IP at arin.net.
b. the company displayed by arin.net has full network and likely server control and is the real provider
A 99.999% SLA means nothing when 90% of the service continuince is beyond the control of the reseller.