Flipkart — Account hacked and ordered product using my supercoins

Actually last week my flipkart account was logged out from my device. I thought that it will due to some application update or something and forgot to login on that day.. Today I tried to login, then on the login page it showed to reactivate my account..at that time also I didn't understand what was happened.. After login back, I went to the orders section and I was shocked that something has ordered and delivered on a different address that I didn't know, also I realised that the culprit was purchased that using my whole supercoins...what was happened to my account..someone hacked!
PLEASE HELP ME.