For me its not recommend to invest in those cloud mining even they are connected in bitmain there is possibility that cloud mining site can be scam.
Because almost cloud mining site are scam they are turn into scam in the end base in what i experience and most experience of other bitcoin holders..
If you really want to make a good income or invest with less risk better to buy your machine to mine bitcoin..
Or for alter native make your own rig and start mining altcoin that you can sell your mined bitcoin into bitcoin..
If they reply and fix your issue better to withdraw them all and invest to other or use the bitcoin and sell it if the price is high and and buy bitcoin if the price is low so that you can make a good profit if the price is increased.
The more you buy bitcoin the more you can make profit because the movement of the price of bitcoin are increasing..