I got a refund when I upgraded to a bigger service a couple weeks ago. They refunded the remaining time that was prepaid. This depends on your minimum contract period - for me, the service VPS 200 G8 that I cancelled was billed hourly and could be cancelled any time, but since it was billed at a 6-month cycle I was refunded the unused hours.
I assume that if you have a 1-month MCP and a 6-month billing cycle you would be refunded the remaining 5 month... but best to check that with support if you want to make sure.
