Shop CJ Network — unauthorised debit

I received call saying that we are call from shopcj and you are one of the lucky customers. You will get one of the the following prizes namely Iphone 7S, Dell Laptop or Cash Prize of Rs.50000. Only we have to purchase of Rs.3500 from shopcj for which we have to do online payment which I did. After the amount for which I have placed order was deducted, more Rs.20000 was also deducted from my account. The amount was deducted for no reason as I haven't done any shopping for Rs. 20000. I am so upset about this. They had all our details such as phone number, name, address. So, I had the reason to believe that it was a genuine call from shopcj. The company has to protect all the data of their clients, so how our data has been compromised. How these fraudsters has all the information regarding us. Please its a request to protect our data and now what I can do to get my money back.