saw this on another forum and it does apparently work
. Print off the voucher : h*tp://www.sainsburys.co.uk/24_7/default.htm
2. Click on "Click here to go shopping"
3. Register
4. Set up delivery slot
5. On the Left it will say Aisles & Shelves: Home entertainment and electrical goods Mobile Phones, Top Up Cards and Accessories, Go here.
6. Select 1 x £10 voucher, you will pay £5 delivery charge when u hand the driver the voucher