Despite the mixed reviews of Hashflare I decided to give them a try.
Bad choice.
Does anyone know if this is normal or whether they have a back log?
Yes, it is completely normal to get scammed by a website like this
Hopefully next time you won't fall for anything like this, think before you buy. Why would they rent out their computing power if it's so profitable? Surely if it were legitimate they'd invest their own money to keep all of the profit for themselves.
I don't even think that these people own any mining gear.