Ghilotti Construction Company interview questions

I was hired on by Ghilotti after completing multiple tests and interviews. I signed an offer letter and put in my two weeks notice at my current job. Days later I receive an email from HR stating I need to complete a drug, background, and credit screening. I was unaware of the credit screening, but was reassured that it was just a basic screening. A week later (the day before Christmas break) I recieve an email stating that my work offer was cancelled due to my credit. My credit wasn’t the best but wasn’t bad either. The fact that they would do this after I put in notice at my job and not give me an explanation or even answer my calls showed exactly what type of company this is. I was distraught and it ruined my Christmas knowing as a single parent I didn’t have a job anymore.