This may seem a paradox but two of my passions are folk music and stock car racing. I am no right wing redneck though as I am a long time socialist who spent years as a labour leader.
jaqui said "Give 'em the money back and tell them that they are no longer welcome to your house." and I agree with the first part, but I would offer them a chance to return.
A few years ago I was at a race at Langley Speedway in Virginia. The race was rained out before the start of the main event. The ticket clearly stated "No cash refund; rain date admission only."
However, I was there visiting family and was to return to Canada before the raindate, so that was of no use to me. I explained to a lady at the box office that I could not return. She said that the track owner was in the office in back and she would ask him about a refund. He came out and was most generous in refunding my money although he had every legal right not to do so. I have returned to that track many times since and my admission total over the years has returned his refund tenfold. If his goodwill had not been there I probably have never gone back. Goodwill is more important in the long run.
As many of you Catters know I am not shy about expressing my views about right wing arseholes like Bush or his Canadian clone Harper. For the most part people on this forum express similar views but we are "preaching to the converted." If we really want to get a message through to others we have to make them think objectivly and to do so first we have to make them listen to our viewpoint. If they feel insulted they will close their mind and any hope of conversion will be lost. I would offer them first a "raindate" free future admission to an event of their choosing. If they refused I would give them a refund with a smile and still invite them back. What may be gained with kindness will often exceed the value of a small admission price.