If you ask me, you were lucky. A lot of people (including myself) got hit with the convoy glitch where if it is attacked, it stays that way, permanently. You can't find it to defend it, nor is it "destroyed", allowing you to build a new one. It just stays "attacked" permanently.
And unless I missed it, despite the huge number of fixes in that recently announced patch, this glitch was not on the list.
Yeah, I read about that glitch I haven't sent out anymore convoys incase I get it. I'm waiting until that is fixed.