I was going to use a new service provider and was looking back for old reference (don't use this site much).  Anyway, I was going to look at old postings for me to get their profile (and therefore phone nubmers as references), but I cannot search by provider name and find them.

Is it normal practice to remove providers?  What does one do about references if this happens?

reasons, see link below.
As for new references, looks like you will just have to start over and establish trust as you did with the lady you saw as first reference.