Vodafone India — Charge 532 + tax on the name of special call 51717

Address:

New Delhi, Delhi, 110018

They charge me Rs. 532 + tax on the name of special call 51717, makes my billing amount Rs.1075 ... although ... normally my monthly bill usage in between Rs. 300 - 400.
phone no. [protected]

my previous month billing amount was Rs. 255 only with normal usage.