Roto Rooter

I had a clogged kitchen sink. I called them and a plumber arrived on time. First he cut the tube, but during this operation, he broke a part, which I do not know the name. Then he spent about 20 minutes in fixing this problem. He did finally solve the clogging problem. When he finished and walked out my house to his truck to write receipt, the total time he spent is about 1 hour. 5-10 minutes later, he walked back and handed in a receipt, but charged an extra half hour ($50) plus the part ($62). The total amount is $314! I tried to argue with this, but the company said that these are all their policies and nothing were done improperly. There are two ridiculous policies here. First, they broke a part, and I have to pay not only the part, but also the time they spent on fixing this part. Second, they also charge the time they spent on writing a receipt, which may take 5-10 minutes, but for extra hour, they charge every half hour. Over the whole service process, I have a strong feeling they the plumber always tried to do something unnecessary in order to extend his service time because their service is hour-based. As long as he exceeds even for 5 minutes, he can charge for half an hour. These people are greedy and dishonesty. I will never ever use them again.