There was a time quite a few years back when a couple refused to pay a bill after their meal because they said it wasn't up to an acceptable standard and when it made the local press some legal bod (or so they claimed) wrote in saying it was a civil matter, therefore there was no power of arrest and solicitors would need to resolve the issue between the customer and the restaurant owner (solicitors are the only winners here because of their legal fees).
Well, as you can imagine pretty soon word got round and there was a spate of dissatisfied customers.
Our advice to restaurant owners was to ask for a downpayment prior to cooking the meal and if they weren't prepared to comply (as potentially harsh as it could be to potential business) the chances were that they were never going to pay anyway.
A lot of restaurants didn't like the idea of asking for said payment and I can't honestly blame them...it would certainly put me off a restaurant.
So when we were called to a non payment claim the customer could only be arrested if they had insufficient funds to pay for what they ordered...otherwise it was a civil matter