One thing you can do is get a "ring" doorbell/floodlight camera.. .it records everything.. install it in your back yard and have a video and audio record of the progress, what day they work, what time they work, when they show up, when they leave, rain days, nice days, etc... So when you sue them your evidence can not be denied!
When progress on our project started to slow down, my wife and I pulled up the ring doorbell archives and went through each day and marked a calendar every day it rained, and they showed or did not show, and if they showed how long they were there.... It was quite eye opening seeing that several weeks of good weather passed with no one showing up... Just an idea.
Example:
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We have do have a nest cam on the backyard! I just need to set up the recording part. The major problem is, there was no set timeline given in the contract. We were dumb and just going off of their word and good references. The only contract timeline is that the shell has to be placed 30 days after dig.