BSNL — deduced my mobile balance for no cause

Respected sir,
I prasanna kumar with mobile no-[protected](BSNL)got a message on my cell that my cell number has won a confirmed prize of 2500$ and to get the amount i should call on a particular number. When I did so, a recorded voice told me to follow a procedure which I could not understand as the voice was very unclear.So I request u sir to suggest me what procedure should I follow. The number they told me to call was +[protected].
Yours sincerely,
I D Prasanna kumar
H.NO. 12-179,
new christian colony,
devarakonda,
Dist-Nalgonda
Andhra pradesh
Pin-508248
PH-[protected]