Basement cracks, molds 2 months after buying house

[Johannie Keith Uy]

Hi everyone!

I just bought a house for personal use, it is a newly flipped house. I had inspection done prior to buying the house but 2months after I bought it, the carpet in the basement is wet. I had a contractor come by and he said there are cracks on the walls and a lot of moisture, most likely floor cracks as well. It also tested positive for mold. I contacted the inspector who did the inspection prior to me buying the house and he said he didn't check for moisture in the basement during that time because the main water valve in front of the house was leaking at that time. The contractor said it will cost me $20,000 to get the basement waterproofed. Is there anything else I could do? Is there any liability for the seller at this point as the house was supposed to be completely renovated when I bought it?  Thank you.