It’s a bit shit mate but it’s stated in the terms when you take the bonus how long it lasts, the cooling off period is designed that way to protect problem gamblers from changing their limits after a bad session and donking off their entire bank account.
I do know how you feel though as I misread the loss limit when I joined up I meant to set a weekly deposit limit of £200 and after losing a bunch deposited another £60 I hit my loss limit for the month which was £200 so then I had to change it and wait the 7 days to play with the money I’d put it, I hadn’t verified so I couldn’t take it out either. So I spent the week playing freerolls on there.
Saying that though they could reinstate your bonus as a gesture of good will but I can’t see it happening.