As above my Mr Wood.. If anything like the complaints the V6 cats receive, then they're just not up to the job. Reports of them lasting a year. The general consensus is a 15 year old GM cat is superior to a brand new aftermarket one. Which is good news, really, in that it's kinder to your wallet.
Dare I say it, but if you're literally looking for a bodgy repair to get you through a matter of days then I'd have thought it as easy as some exhaust bandage, with some large jubilee clips/ similar either end to cover over the flexi. I'd probably trust the exhaust bandage more than that tape, but I've never used that tape stuff, so based purely on gut instinct. The bandage will be able to flex, too.

Admittedly not on a flexi joint, but a mate of mine has an old coke can/something like strapped to his exhaust, and it's 'fine.' Not professional, not pretty, but does the exhaust leak? No. Ooops, it's blowing again, whack another layer round it. Drive off. Sorted.
As Kev says, it's all not going to last very long - but then again, you're just after a quick repair until you can sort something better out. Hope you get sorted soon
