I have been called also from the same number and saying he is from City bank, it is totally suspicious and they are not from Citibank. don't provide them with any information, you need to ask them to write you email or ask them their employment ID.

He said he was from Citibank and asked questions confirming identity. First letter mother’s name and month of birth, and confirmation of current address.

Claimed from Citibank but not sure. Sounded suspicious