Aha! I knew it!
That ransom note was a diversionary tactic by some scheming get rich quick merchant!
The yoghurt has been spotted enjoying its time in London, doing the sights and sounds of the capital city. Clever of it to get a bus really - with no legs it would take ages to be casually kicked around London by passing feet...
I hope it manages to stay out of the way of any sweepers and road cleaners!