Google Play deducted extra Rupee 50 after first-time Play Store purchase of an App/Game. Why is that? Today I bought Temple Run: Oz from Google Play. When I filled all the credentials in to pay rupee 53.18 for this application then it automatically deducted rupee 50.00 from my credit card and after submitting it again deducted rupee 53.18 from the credit card. But the original price of this game is rupee 53.18, why did the extra rupee 50.00 deduction happen?

How can I get this money back?

Is buying an application on Google Play not secure?
Don't worry Vinit, one of the standard way for payment gateways (including Google Checkout and PayPal, PaisaPay etc) to validate your account is by deducting a small amount (typically 1 USD or  an approximate equivalent 50 INR) and returning it in next few days. 

Please wait for few days and while doing so, please observe for any reversal of 50 INR. If you see a credit to your payment account then all fall in order.