I did the 2 signup offers with Spinit on 25th November, buying in with a total of £200. I won £546.75 on the second offer so submitted the withdrawal. The account was quickly verified but after speaking with live chat a month later the withdrawal was still pending. This stayed pending until today 25/1/18, when I received an email advising me of the following: "We regret to inform you that your winnings have been removed due to a breach of our Terms and Conditions during your game play". Not once do they specify which term was broken, probably down to the fact that none were.
I have spoken to their live chat since receiving the email but they weren't very helpful. They simply pasted the same text I had received in the email, in the chat window and then advised that there was no more that could be done.
I am careful when using bonuses and always read the terms so know that no terms were broken. I made sure that I was within the maximum bet size and the game I played was allowed, so they should be paying me what has been fairly won.