Pensioners discount at the different stores is inconsistent

I was at the Spar in Balfour yesterday morning. While every other Spar I shop at I get a pensioner's discount except for Balfour. Apparently, each individual spar has the right to give or decline this discount, which, I must say is very very concerning as Pick and Pay and Checkers give it to me country wide no quibble this seems very unfair that Spar has two different rules that seem inconsistent with their advertising.