zomato food app - Food not delivered and no refund of amount paid

I placed an order (order number **********) on Zomato on **.**.****. The delivery person arrived at the location but refused to come to my place upstairs and spoke rudely, over the phone. saying "niche bhi nahi aa sakte tum log". When I confronted him over this and asked what kind of language is this (I recoded conversation also), he did not come and marked the order delivered to me. I raised the issue and the customer support executive arranged a conference call over which delivery person again spoke rudely and said he handed over the food item to someone.
The customer support executive expressed his apology and offered to return Rs. ***/-, I spent on the order, in the form of prom code. If I place the same order I have to spend Rs. ***/- not Rs. ***/- (as **% off was there in the form of promo code). Money does not matter here but the kind of remedy you have proposed is costlier to me and that too with a no-fault if mine.