Tata Sky — Debit account balance

Address:

411041

A tata boy (?) called to from a spam number. by mistake i received call, he was telling me about on scheme of HD channel free for one month. I told him i dont need such a free schemes. but during this call he (so called and hacker boy) debited my account.
I have shocked after reading messages.
My question is such a call boys/girls are taught to hack the money of customers while training ?
are they live such a hacking money ?
tata is not capable of paying their salaries ?

or what ?