Yes, she was asked to stop using her phone. More than once. Each time it moved a little further away, but never far enough. She'd just decided to carry on with whatever chat she was having before I walked in.
Thought I might have been a harsh in suspecting she was trying to provoke me to walk, but later comments suggest this may have been true.
Given her shit attitude, and that I knew my self control was close to it's limits, it was best to avoid trouble and write off the money. In a sense, those who read this, and otherwise might have visited get it back for me.