In April 2013, a Manager of Punjab National Bank who is a resident of Sector 21 in Chandigarh, complained that after he used his credit card to pay for fuel at Sector 21 Petrol Station, his card was cloned and used for shopping of Rs. 36000 and Rs. 20,400 in Ludhiana. This is the link to the news story: http://www.indianexpress.com/news/bank-manager-says-credit-card--cloned-/1103066/
Why it happens
The problem here seems to be that most of the times, card swiping at petrol pumps does not happen in front of the customer. People keep sitting in their cars while they hand over their cards to employees of petrol pumps. When debit cards are used, many times the staff of petrol pumps bring the POS machines to the customers for entering their ATM PIN. The PIN is entered in front of the employee. Now the petrol pump guy has a copy of your debit card and he has seen your PIN. You don't have to wait for long before money starts disappearing from your account. And if you have not activated SMS alerts, the news of theft from your account will arrive at its own slow pace.
What to do
Do not use Debit / Credit Cards at Petrol Pumps. If you must, get out of your car and watch the whole process. Make the staff look away when you enter the PIN. If you have not activated SMS alerts for your card transactions, do it now.