I used to receive lot of calls from citi/abn amro/hdfc/icici banks for credit cards, personal loan, insurance & what not. Initially they were increasing my vocabullary in money market but later on it was very annoying. Initially I used to poliately reply in 'NO', later on used to hang up without replying but when nothing worked, following proved to be master piece.
Everytime I used to get such calls, I said, "Sahab toilet gaye hai". I got about twice or thrice a repeat call but then it literally stopped to a level that when I was in need of a personal loan, I was required to walk in to a bank.
