Reliance Mart — replacing goods

I purchased 2 packs of sugar in r-mart where they charged for 100 (9 per kg), when i asked for replacement, manager said as per terms and conditions it cannot be replaced after billing. I am not an r mart employee to know terms and conditions and offer is only for purchasing above 1500.. At least in counter they have to inform it cost 50 per kg when common people (Who buy below 1500 rs). Taking money from common people and giving offers to rich is very embarrassing. And mangers not knowing how to resolve issue is bad to there profession.

Sneha