The electrician's estimate on the project was $13,000. I paid the $13,000. Then he later asked for $13,000 more. Then after the project was finished, he submitted another invoice for $13,000 more. I have asked him for a detailed accounting of how he came up with this. He has refused to respond and filed a mechanic's lien. I'm appalled that he tripled the cost of the project with no discussions along the way. I feel like I'm being gouged. Any advice?