LONDON, 2015-4-14 — /EPR Retail News/ — In its biggest ever points giveaway, Sainsbury’s is giving customers the opportunity to boost their Nectar balances by filling up at Sainsbury’s petrol stations, where they will be rewarded 10x Nectar points for every litre for a whole month. For more information please visit Sainsburys.co.uk/fillup Sainsbury’s rewards customers for…