Please note, Any bank or their vendors will NEVER ASK for your CVV, PIN, OTP or Internet Password. Never share such information with anyone.
Call made by fraudster give one’s assurance that this call is from bank and try to convince caller with different offers like 40-50% off , free coupon , free yearly credit card update and so on. and collect details and try to cheat peoples.
To avoid this frauds one can use latest application in their handset like truecaller which will be beneficial to detect the calls and later add it to block list or better never share any banks details on phone and be at safer side. If you are being cheated then within 10-15 mins call the customer care and investigate about call so their are some chances of refund of such fake call.