Sagar Ratna — charging way too much

Address:

Meerut, Uttar Pradesh, 250002

We ordered North Indian Food and told the waiter to bring onion for us. When the bill came, we saw they have charged us Rs.100 for that. This is what we get free in all over India with North Indian Food. Even the local shops would give you onion along with the food.
When we went to the counter regarding this issue, they did not even listen to us and argued. Paying Rs. 100 for a piece of single onion is way too much. I didn't expect this thing from Sagar Ratna. I am highly dissatisfied. This has never happened with us anywhere.
Please look into this matter as soon as possible.