Uber Cab — Free coupon code

Address: Kolkata, West Bengal

My name is Rajiv Jaiswal.I have installed this UBER application as my friend reffered me to install it where i will get 300 rs free ride for installation.I have installed it.And 300rs is showing into my Uber account.After that i refer this to one of my friend and for which i again got 300 rs..collectively 600rs.is showing into my account.But i cant use it.I have tried to contact to Uber officials but neither they have any customer care number nor any helpline.I have send so many mails to them regarding the same but all the time they are giving negative feedback.They are telling that your free coupon has been expired.But its not true.I am attaching the screenshot of that page.Kindly help