Jude, I've got an incomplete set - here goes:

When you're tired and depressed and feeling lonely,
When your chequebook's in the red and you feel blue;
When you're glad the XXX are open or your rubber band is broken,
Or you drop the toilet paper down the loo.
When you're feeling such an urge to wash the steak knives,
Or to sniff at the exhaust pipe of your car;
Or to farewell all your friends and take a nap inside the oven,
Stop! Salvation's just a suck from where you are.

When you're feeling down the best way up is chocolate,
It's the answer that will get you through the day.
Let me get my teeth around something small and square and round
And I'll masticate until I feel OK.

Now when God had finished making all the heavens,
And the mountains and the valleys and the seas,
And the weather and the weevils, and the squid and German measles,
And the gherkins and the cockles and the fleas,
On the seventh day when He was sitting resting;
He was feeling in a very chipper mood.
then came one last inspiration for one final last creation;
Something fit to please a god that could be chewed.

When I see a bar of chocolate lying idle
It always seems to find its way inside my jaws.
It tastes better in than out, it's a shame to mess about,
for it's going to a very worthy cause.
And although it won't endear me to my dentist
And my doctor will be fearful for my health,
And it's given me a skinful of enormous oily pimples,
I'm still feeling very good about myself.

That's the version I got from Moira, but someone sat on the mike at the crucial moment, so there are a few dubious bits!