I hired a contractor to put up a fence in our backyard. I showed a contractor stakes in backyard. Contractor told me the house behind us surveyed their yard and still stakes are there and connect these stakes. He told us that we don't have to survey, we are safe. Next door complained the property line to the contractor when he started working, he ignored and finished putting a fence. (I was not home during construction) We surveyed our yard and found out the contractor put fence in next door's property. Who is responsible for paying removal. Us or a contractor?