Is it the EU Court of Justice that has jurisprudence?
If the service was purchased in the UK it may well be a matter for the UK courts. Simply stating that EU or USA or any other law covers the contract does not allow the provider to arbitrarily stop providing the service because they want to throw their toys out of the pram.
I am not aware of who has authority here but would not be too sure it was EU law anymore. Worms - can - can - worms.
Legal squibling and trebles all round!