The conflict between the mail shot and what is actually going on is interesting.(posted 7982 days ago)1, The Advertising Standards Authority
I'd suggest making a complaint to the ASA. Make sure that you identify the company at the front, and the company behind as well. Both are guilty of offering goods or services, when in reality they are just trying to confirm you live there. This is a violation of the Advertising Standards Code, as such it applies to the front company, but for Citibank it would be a disaster.
2, The IC
I think an assessment request to the IC should provide the same details, they are not allowed to dupe you to obtain personal details like this.
Good Luck.