problem customer calling me back to repair something under warranty

my worst customer of the year that sent me a hate letter in the mail after the job was done is now asking me to come back and do a possible repair on my work. I give a 1 year warranty and he's under the 1 year



he had a rotten sewer pipe where his sewer left the house. in order to repair it I had to dig up outside his house and run a new pvc pipe into the house. I completed the job in record time and he tried to renegotiate with me after the job was done (it was a bid job/ Not T&M)....I told him since I could not charge extra if the job took extra time that I would not discount if the job went well......he was obviously angry with me, but paid me



then he sent me a long letter saying im a con man and how I must be laughing at him for how much money I made....it was a very odd letter and the person has some conspiracy issues....he thinks I planned it all out to screw him.....I wrote him back with the facts



so now he's getting sewage in his sump pump.....odds are it IS my fault...something shifted and the rubber boot may have come off underground



I can tell if I made a mistake just by removing the cleanout cap and looking down the pipe...so I don't have to dig it up if it isn't my mistake



I asked him to look down the pipe first



my wife says I should just ignore him....blow him off.....his letter scared her....she had worries this guy would come to our house it was so odd/aggressive



I have decided if he talks to me abusively I will walk off the job....I will warn him about this ahead of time.....tell him to treat me with respect or im gone



should I give this guy his money back? let him hire someone else? or should I go fix it?

via Small-Business-Forum.net http://www.small-business-forum.net/managing-your-business/10339-problem-customer-calling-me-back-repair-something-under-warranty.html