The recednt comp is a waste of money

I have tried several times to enter this competition as I use a lot of yoghurt. Every time I answer all the questions and when I try and enter the code I get the response invalid code. It makes no difference if you enter the code on the container or the code on the little yellow sticker (which is on some containers as I presume the other code was illegible which was far easier to read) same reply every time, a lot of times I get the invalid code message as soon as I've dialled the number. Beginning to think this competition is a ****. On most of the containers the code is not legible.