Zomato — No resolution over missing item delivered

I ordered idli sambhar, pav bhaji and gulab jamun from zomato. But the restaurant owner only give pav bhaji and gulab jamun in order and idli is missing. Delivery boy calls me and tell me that restaurant owner given half order and tell to deliver it and not to tell me about Missing item. Even restaurant owner switched off his phone
Also zomato costumer support not responded to the delivery boy and me. After that order is delivered to me and I registered a complaint but the zomato support telling me that they can't help me in regards . I have all proofs