uber eats pune - promotion not applied

order no **BBC, I have ordered three items and all items were eligible for **% off. on screen it was saying that get at ** on checkout but when i place order full amount were charged. I tried to cancel but they told me that its can't cancelled as its accepted by shop. and if i cancel i will loose money as well product delivery. I raised a complain to customer care they refunded *** where *** was expected. on mail they have accepted that it was system problem but still they are not refunding remaining amount. I have all evidence on mail ,if you need i can share mail communication and screen shot of products and offers. i am following since last almost a month but they are not responding. please help me out