Due to the fact that my problem Quorn Lasagne wasn't an actual Tesco product, I wasn't really expecting much of a response out of them regarding my 'unwanted item'; however, this morning I received an apologetic letter with a £5 Tesco Moneycard attached (no idea what a Moneycard is - must google to find out more.....!!!)
"I'm very sorry that you have found a foreign body in your Quorn Lasagne. I understand how concerning this must have been for you." (Actually, now they've called it a 'foreign body' I don't think I ever want to eat another quorn lasagne). The £5 was to cover the cost of the product, which although I can't remember the actual price, was certainly under £2.
The also said that as it wasn't a Tesco product they can't deal with this personally (which I fully accept) and that the supplier should be in touch within 21 days. I have a freephone number to ring if this doesn't happen.
At my age I'm not easily impressed by much, but I have to say that Tescos have done a jolly good job regarding customer relations this time. Credit where it's due - well done Tescos!