I don't think this person had a private message, because this thread post is his first and only one. 5 posts are required before private messaging is enabled. Unless he made more than 5 and they were deleted, but I am doubting it since the OP hasn't been back to this thread since posting it.
OP could be talking about a deleted post, in which case he should us the Contact Us link to seek administrative assistance.
Call me cynical, but I don't think either are the case in this thread. I think it is a spam posting of some sorts.