Write to them if you want to see the show return with the old/new episodes and additional airings:

Lifetime Television
309 West 49th Street
New York, NY 10019

and/or

Lifetime Television
2049 Century Park East
Suite 840
Los Angeles, CA 90067

Well, it looks like the emails worked(that's all I have sent so far, I was planning to sent a letter through the mail next week, but I think I will hold off for now) since Unsolved Mysteries will be back on Sunday Mornings at 1am ET/PT.(I do encourage we continue to email them and try to get it on more in January, but for now I'm happy. One showing is better than nothing, and the good news is, the new segments for most of the episodes airing, I have not seen(see the Unsolved Mysteries will not return post for episode details)