Citibank Credit Card Complaint

Citibank Credit card department,

Credit line increase/decrease Kansas

I have a CITI Diamond Preferred Card and was given an $1800.00 credit limit. I have never paid late, managed my credit limit responsibly. I make over $ - annually and have more than enough resources to pay the obligations on this card. About 2 months ago I receive a notice from CITI indicating that my credit line was being reduced. I did not agree with the this decision and called to complain. My credit line was reinstated and I was told that I should not have this issue again. On -/-/2016, I received an email indicating that once again, my credit limit was being reduced. I called again to complain and they submitted my claim for reinstatement. This request was denied. There is no reason for CITI to be doing this since I have paid my account in full almost every month and have not given them any indicators that I would be a non-pay risk