People here recommend supermarket bars - ASDA I think, measure up bars - cranberry something is said to be delicious and they are cheap. Biggest Loser Bars people have said are just yum. You can also use Atkins Advantage bars (not Endulge, they are not meal replacements) as an emergency thing but only for one meal a day.
Try two bars a day and perhaps a protein Ready-to-Drink meal replacement shake (or protein meal replacement bar) from the low carb section of Holland and Barrett or one of those muscle-builder shops that are everywhere now. Or two shakes a day and one bar, but check they are low carb and high protein. I recommend EAS MYOPLEX shakes. Full of vitamins and minerals and packed with protein. Think Holland and Barrett do those, too. If not they will have something very similar.
Don't panic! These high protein subsitutes will see you through until you get your next lot of products.