Powervps downtimes!

I’ve acquired a vps from Powervps since they seems affordable. But after 2-3 weeks, I experienced so much downtimes on my sites which happens everyday in a specified time. I’m not sure if its with the plan I chose but at least they could have advised me then whether I upgrade or not. There’s always a certain time of the day when all my sites can’t be accessed. Their support is quite fine but I just transferred from another vps where I’m happy right now and considering they have the same features and same level of price.