Strangely am filling up the Jag today at Sainsburys using my 12ppl off voucher which expires today

So am reckoning 58l LPG and 42l of unleaded....they are always confused when I do two seperate fuels from the same pump and have to consult someone for me to get my full £12 off. That mean I end up paying £1.17 for the unleaded and £0.63ppl for the LPG (so £85 in all)

As I read the voucher on this link it's is for 'shell fuels' where the LG sold by Shell isn't actually a shell fuel and they use someone else to supply/deliver/maintain...which could be the reason for their reticence.