When I was 17-18 and I moved out of home into my own flat I read the T&C on my first utility bills carefully.
I recall reading in the T&C that my utility company can cut off their services and keep any money they have of mine, and offer no reason for this.
I have throughout the years brought this up in conversation with friends and family. I recall one person saying; "Sure, they have those T&C but they would never use them."
In any case, I feel uncomfortable doing business with those kinds of T&C.
I've always thought there should be laws preventing companies from having unreasonable T&C.
There are here in the UK
So many companies fall foul of these laws here that it shows that unchecked, many companies would behave badly.
If a company "would never use" a term, why would they bother having it there?
UK utility companies are the most caught entities breaking UK consumer laws. One water company even got prosecuted for fraud, a criminal offence, because they supplied false data to the prices regulator in order to get away with increasing prices way more than they needed to.
The down side is that so many companies have a few dodgy looking terms that anyone who took a zero tolerance approach (as a customer) may as well live in a straw hut in the middle of a field, providing for all their own needs.
One just needs to be aware of what they might pull, and prepare accordingly. In your example, this would mean keeping a close eye on usage and payments so that the utility company rarely, if ever, has more of your money than you have had of it's service. This has actually been something that our regulator has cracked down on recently. New rules require utilities to refund surpluses to customers on demand, rather than merely adjust payments at the end of the cycle. Just recently, the regulator has ordered utilities to hand back surplus payments they ended up with when customers changed supplier. In the past, they were keeping quiet about it in the hope that customers would not notice that their over payment didn't transfer to the new supplier along with anything else. It's now costing them more to trace these old accounts and give the money back than it would have done had they been honest and had a system to automatically refund surplus payments at the changeover. They DO have a robust system in place when it comes to getting what they are owed from a final bill when a customer changes supplier.
With casinos, maybe players can fight back in a different way.
Normally, where a player stops playing somewhere, they get that "we missed you....." email and offer. It might be an opportunity to reply. "Yes, I was a regular player, but then I noticed this term had been added since I last checked <quote term here>, and so I looked around for somewhere else to play that did not have such a term.