Someone bought a painting from me on craigslist and they sent me a check overpaid me and wanted differance.?

They didn't give me phone numbers that worked, they gave me a check and it is for 2,000.00 more and he wants me to give him the 2,000.00 when his shipper picks up the painting. I think it is a scam. What can I do. His name is Bisi Camara. Please help me.