Organic355
I would put posters up NOW.
Mention the Street you live in, if Frankie has a chip fitted, give them a call, some good advice here:
http://www.catchat.org/lost.html
We went throught the same thing at the weekend, we lost our daughters new 10 month old kitten for two days!
We put notes through all our neighbour doors, some 80 odd flyers, plus signs on all the lamp posts on all the surround streets.
We had lots of calls.
We heard him crying on Monday night at 2am in the morning to get in!
Fully fed, smelt of purfume, my guess is he was locked in somewhere.
Hopefully Frankie will do the same and find his way home soon.