IndiaCakes.com — Cakes and their order

I ordered a cake for 549 rupees and applied discuount and opted for normal delivery. but after few hours i receive a call asking to make a payment of addditional rupees 150 which wasn't mentioned during the order. Later, to confirm when i called the helpline no. [protected], the people are so rude they just bang the phone and never answers any calls.
my order no. was 1725211.
kindly take action