I laughed a bit at the sheer ridiculousness of this 
Wanted to buy the Tesco £10 meal deal there (main, side, dessert and drinks for 2) but there weren't any drinks left in the fridge for the meal deal. I went to customer service and asked if they were going to be restocking it shortly or if I could have an alternative drink. No stock left apparently and I couldn't have a different drink as the till wasn't programmed to accept it. And, no, they couldn't override this either.
The drinks are usually glass muktipack bottles of Cola or diet Cola. There were some of the same glass mutipacks in the fizzy drinks aisle but were for Coke Zero. No,I couldn't have these.
Of course i didn't buy the other bits as that would have come to over £10 without the drinks so I left it.
Aibu to think this was a bit nuts that Tesco would turn down a sale because of this? And what are they going to do with all that food stock if someone doesn't replenish the drinks soon? No one will be able to buy the deal! 