I’m from hyderabad and I’ve been purchasing from bigbasket for last 8 months. I have spent around 30K so far on grocery and other items available in bigbasket. I have NOT faced any issues till now. Their delivery is very prompt, they give discounts and you can purchase from the comfort of your home.
There are 3/4 instances when I received spoiled vegetable/egg. But when I called them, they immediately refunded my money and asked me to throw those items. But this can also happen if you purchase from bigbazaar, more etc and noone will give your money back. Also you have to struggle for parking, stand in queue etc.
So based on my experience, this is the best place for shopping groceries.