Ring your local Trading Standards Office
If you get nowhere with them, contact GlaxoSmithKline, who make Lucozade.

Also feel free to report to Trading Standards any robbing shops/petrol stations who don't have their confectionery price marked anywhere. The price must be on the shelf edge or stamped on each item. YOU SHOULD NOT HAVE TO ASK FOR THE PRICE. When charged 58p for a king-size Snickers, it gives great pleasure when passing the same petrol station two days later to see Trading Standards with their calibrated fuel cans, giving them "the works"...
( eXOBeX, Sun 22 Feb 2009, 23:19, 1 reply)

AFAIK
Shops can charge whatever they want for their goods. No-one can make them charge the RRP - that's what the first R is for.
(CannedLaughter, Mon 23 Feb 2009, 0:20, closed)

True, but
Shops aren't allowed to advertise one price and then charge another.

The advertised price is an invitation to treat, not an offer, so the shop is entitled to refuse to sell, just not entitled to change the price as a condition of sale.
( flake has nothing against your right leg, Mon 23 Feb 2009, 16:13, closed)