By Julia Banim A flight attendant has shared how she punishes passengers who refuse to swap seats – and you may not be too happy about it. For years, a fierce debate has raged over the etiquette of seat swapping on planes. Some believe that if you’ve paid for a seat then absolutely nobody should have the right to request it – and understandably so. Others however argue that, under certain circumstances at least, you should make allowances and give up your precious seat to those who need it more – even if you have managed to bag a coveted window seat. Now a savvy air hostess has revealed her tr…