Is this contractor scaming me?

I am in the process of buying a house we are at settlement. The loan company wanted a contractor to look at the roof and the back left gable. He said we needed a new left gable and that 50-60 shingles was missing and needed to be replaced. We confirmed with him directly this was all that needed to be done. We done the work we put on a whole new gable and replaced over 100 shingles he came out again and said it was ok we done the work.When he sent my brooker a fax it said yes we replace the gable but did not paint it and the shingles was replaced but we needed to replace the west side with new ones. I am so pissed he stright out lied to us. He told us it was ok. then he told us we had to pay him 75.00 each time he came out that was 150.0 we was not expecting and now he has to come out again and see the work is done. Can I make him put in writting the outcome of the next inspection so he can not lie and say it is ok then turn around and say something else is wrong?