Fundraising with supermarket vouchers - anyone know how it works?

[Hangingoninthere]

We are trying to find new ways to fundraise (aren't we all!) and I have seen that several schools offer a voucher scheme where the PTA sells supermarket vouchers for waitrose, sainsburys, ocado etc at face value to parents and the PTA gets commission on all sales. Here is one scheme www.lcpspta.co.uk/app/download/5791925354/Supermarket+Vouchers+Flyers.pdf
I have tried contacting waitrose, John Lewis & ocado but am getting no where fast. Sainsburys is a bit easier as they have details in their website.
Has anyone got any experience of a scheme like this and how to set it up?
Any help much appreciated!!

[irregularegular]

I've not come across this before, but as PTA chair I'm very excited about it - will be watching this thread for replies!

[Hangingoninthere]

Finally managed to speak to the right person at John Lewis - they are no longer operating the scheme which is a shame!