Price protection is for Long term payers. if u subscribe for 1 year then u will be safe and protected if any hike happens till ur next recharge date. here D2H has reduced it to 6 months as they hiked . .
If u recharge for 1 year on April 1st 2013 then ur next recharge is April 1 2014 . ur account doesnt effect untill April 2014 if any hike but here D2H made it as u have to pay the hiked price after 6 months itself.