Hashnest
KNC
Gethashing
BW

Those are just a few I know of off hand because they provide proof upfront. I'm sure there are a few others you could find by tracing the payments but I don't waste my money on cloudmining so I couldn't tell you.

BTW, you I mean Cloudmining.website will have to come up with a new bullshit excuse for why you they can't provide proof of mining because surely nobody will be "paying a premium for freshly mined coins" when they can buy them for a huge discount from an actually trustworthy company. https://hedgy.co/mining.html