This quote from Bill Schwab seems relevant to your situation Pelican:
"Any changes need to be documented, and if they don't agree to signing a change order, the job stops until they agree. There should by all rights be penalty clauses that the client should pay if that occurs. Also account for office time, over and above field time with your change. We have a mandatory $300.00 charge plus put of pocket expenses for EVERY change that is made...This means that if someone is willing to pay the $300.00 to account for the change, they are serious enough to go forward with it. We have had them decide on a change, only to change back several times until agreeing to do what was originally planned in the beginning. By implementing such charges, we get compensation for our time."
from the thread
Busybodies