People are cheap, greedy arseholes on this island. Ask any independant contractor and the bane of their existance is people who wont pay on time, wont pay the agreed amount, or wont pay at all. And you can be guaranteed the worst offenders are those with money, and you've no chance of getting them to pay up front.
It's all well and good saying to go to small claims court or via a solicitor, but when you're dealing with amounts in the high hundreds or low thousands, its generally not financially viable to go after the cunts and they know it