Hi Arum, haven't got time to read the whole thing yet but as far as the wedding flowers go it states in my terms and conditions that due to whatever (flood, famine, plague of frogs) colour, shape etc etc may vary or may not be available and substitutions may have to be made, the bride signs it in front of me and she gets a copy and I keep one and I always make sure I explain it to them aswell. I think that so long as you have this sort of thing in place it would be very hard for anyone to sue you, unless it really wasn't anything like they wanted. As for day to day trade if people pre-order something we have to get in we always take a 2nd option - just in case. As for your customer she sounds like she wanted something for nothing so wouldn't worry too much about that one