The most common I experience are calls for bank asking me for personal information, saying its safe, my response always is i don't give information via call, and let them look for information on what they have, but even though they give info about me I don't confirm any, instead i ask them to email their concern, and they never bother me again, also received a call asking me if I'm interested in investing and that i have the account which i do not, asking me also information, but i just reply I'm not interested and block the number.
Those calls are never from banks but from scammers disguising themselves as bank agents trying to get someone rid of their hard earned money. Bank officials will never call you to request for personal information via phone calls. They have made this clear to their customers that sensitive information should not be shared with any of their staffs via phone call or text messages but people still find it hard to abide by this warning and end up being scammed after sharing their information.
To be on the safer side, never entertain long conversation with strangers via phone calls. The longer you stay on calls with them, the more you're likely to be convinced.