Unresponsive sponsor - is this normal?

Hi everyone. I'm attempting to close on a condo in Bushwick (1206 Putnam/499 Evergreen), and the sponsor has been very unresponsive to requests. I'm requesting an extension on the closing date, as the preferred lender of the building needs more time to close. I would have been set up with the preferred lender sooner, but I only received that lender's info a month ago despite being in contract since November. Closing is in less than two weeks, and sponsor has not responded to requests from the preferred lender nor its sales agent, and the sponsor's lawyer has not responded to my lawyer. I can't escape the feeling that I'm being scammed. Is this normal?