Fair point MurciPete, but then again why the hell shouldn’t he try, i mean a lot of casinos play that game with the players by using vague terms etc to void winnings. Not saying Sky do i have yet to have any issues with them myself.
These days though most if not all casinos require you to have a chat on the phone to make sure you are in control of your gambling, aware of deposit limits etc before they make a decision to allow you to play there again so there could be a case for complaint.
So you self excluded for 5 years with Sky and reopened an account and it wasn’t flagged, you could have a case like is said, im not sure though as the 5 year exclusion on the other account has ended.
Probably best to ask over at casinomeister forum they know a lot regarding SE issues and whether you have a case to argue it.