How can this be right?

I havent gambled for a while, but bored at work so uploaded £10 just to pass the time. As soon as I went into Casino they automatically gave me a £2.50 bonus without even asking if I wanted it. I made my £10 into £50 on poker and roulette so went to withdraw it and it wouldn't let me. It says as I had a bonus I had to stake a minimum of £250 to claim my winnings back!?! Meaning I had to bet another £218.00 something just to take my money out.
I could withdraw my original £10 but my £40 winnings would be removed and un redeemable at a later date. So I carried on playing, got up to £78 but then lost it all as I had to keep playing to meet the £250 stake threshold.

Fucking scandalous!