"In essence the law is that no person can force another to enter into a contract with them, the striking of a wager being a contract between parties."

This is coming from the laws governing the relationship between shopkeepers and customers, where any shopkeeper can refuse service.

The situation here is entirely different in my opinion.
By opening an account we enter into a contract to conduct wagering.

That is the contract.
The fact that it is written in a way to benefit one party only is the problem.
If the govmnt, benefits from license fees it should be able to dictate some contract terms to make it more equitable to punters.