Citibank — Citibank account blocked without any genuine reason.

I hold citibank saving account for last 6 years.

I often travel abroad and back to india.
As a result sometimes its hard for me to be in my specified mailing address given to citibank.

Incident date : 09-june-2017
I happen login my citibank and transfer funds, but my transfer was not successful.

As a result, i contacted citibank customer care and i found that my address is not updated to my latest address and they blocked my bank account.

As i am outside the country, i informed i cannot come and submit my address proof of my residence in india instead i can send via mail.

Citi agreed for that and given me address [protected]@citi.com to send my address proof.

I have sent my address proof and i have received an e mail with issue number : 'citibank=[protected]' address proof - citibank.

After that citibank says, they cannot unblock my account till i send handwritten address change letter via post.

This is not solved after so many follow ups.