I had an electrician do damage to one of my interior gas lines. What type of lawyer works cases like this?

This is the second time this electrician has done damage to my home. The first was a failed neutral wire that fried all of my appliances. Now the house is leaking gas right were they fixed the neutral and we have been breathing this gas over 8 months. To the current answers. We could not find the problem and neither could about 6 contractors. I have all the paperwork. And no, I am not dead or stupid thanks for the help diq. It's a small leak in the garage wall.