Payment gateways must be routed through the right merchants. For POS sales in stores, use the device provided by reputed banks. There is no hold period on your transaction. The swipe machine will cost you a refundable deposit initially depending on the model and type( wireless, phone line modem etc) . However if your transaction volume increases there are credit back schemes. You have to negotiate with the bank/merchant.
For online payment transfer, paypal and rupay is instantaneous. Even Airtel is coming out with their gateway. You can spot fraudulent sites when the SSL protocol does not appear in the URL. Customers too are wary and will not provide CC information when the sites do not have https.
I hope this helps you. If you need any further assistance please post here.
