Zomato — Partial order delivered

I have placed an order of 2 nutella banana waffle through Zomato, i made an instruction in the app's "Add Instructions" section stated " please send Nutella separately" and which was Accepted by the restaurant. I was given order without Nutella, tasteless waffles. When I complaint about the restaurant to Zomato, i was told that i was supposed to call the restaurant but there was no information that i need to call the restaurant if i make instructions. If there is call required, the app should say so, or it's should not have instructions writing option. The customer support offered only half of the refund when I couldn't eat the entire food.