Issue with construction manager

[Ashley Zhang]

Hi all, i am building a new construction, a single family home to sell. This is my first real estate investing project. I hired a project manager to oversee the project. We agreed upon the time schedule and budget at the beginning. When i contacted him for updated info, he told me that it will be over the budget because a couple of his subcontractors went to other bigger project, so he has to find new ones which caused the price went up. Also because of that, the completed date will be postponed. He also told me that the market is so hot so its hard to find contractors willing to do small project like mine, so its hard to keep them around. A couple of sub contractors took several jobs at the same time caused my project being delayed. So my completed date is literally a month longer than original one. I asked him if he will pay them less since they didnt finish on schedule, he said no. So the house is supposed to be completed at the end of November, now is postponed to December. I am not happy with this manager, but i dont know what else shall i do to save this situation? Please share yours thoughts. Thank you!