I think it's an interesting challenge to the Equality Act either way and will see the answer come down definitively on one side.
For the reasons above, I don't find the behaviour discriminatory and if it is ruled as such I think it's stupid. Businesses SHOULD be perfectly allowed to discriminate their sales and purchases if they so want - the foundation of capitalism is to allow the market to decide the suitability of business practices and not the state.
I also think that people should be allowed to refuse service to Muslims, gay people, black people, fat people, French people, kids, and anybody else that they so choose. Businesses are not people and should not be held to discrimination laws in the same way as people. Let the consumer decide with their wallet to support or protest the policies of the business.