Desperation - Last Minute

Still looking for a summer internship that is finance-related. Honestly, did not think it would be this hard to find even an unpaid finance (anything related to finance) internship in New York. I'm a masters student at Columbia and all I have now is an unpaid internship offer at a development financial advisory firm that contracts with WB, IFC, etc. but I would be doing market assessments, research, etc.... no excel... Should I accept or turn them down in hopes of miraculously landing something better in the next few days? Where could I apply? I just want to practice excel and finance in a private firm during the summer, even if it's unpaid. (btw I don't have any finance experience)