Somerfield/Co-Op have 10pk x 330ml (fridgepack) of Coke/Diet Coke on offer at £3.99 or 2 for £5.50, not a bad price at 27.5p per can.
Some stores (EDIT: SEEMS TO BE THE OLD SOMERFIELD STORES THAT HAVE STOCK) also have packs that have 50% extra free so you can get two 15 can packs for £5.50, which is only 18.3p per can (see photo in post below). Even better than the Sainsbury's deal from last month!
In the store I spotted them it was only the regular Coke that had the 15 cans, the Diet Coke was just the standard 10pk.
Thanks to sunkissed for the additional info:
The deal expires 23 March and though the 10pks are available nationwide, it'll just be your luck whether or not your local store has any of the 50% extra free packs in stock.
Not sure about coke zone points, as there is no mention on the packaging, I just assumed they were in all the bigger multipacks.