Tennessee Land Title

In mid May of 2019, the potential buyer met with the husband of the property to be sold. The agreed purchase price was made and the seller wanted to provide the closing documents. The buyer then agreed to to having the documents completed by his company of his choice at the closing price of $50.00 to the seller and property taxes due for pro rationed of the year to the seller. The closing was to take place on June 10, 2019. The owner attended the closing and the check was not issued for the agreed on amount. The title company did not accept the buyers check and the seller signed documents without going over the closing costs . Now, the middle of July the potential buyer is already building g on the property and the buyer had never received the check or direct deposit for the purchase of the property. The seller called the office of the insurance company to provide the correct amount to be issued on June11,2019. The buyer has emailed three times in the last month and called again. How legal could it be to have someone building on the property that had not cleared to the seller?