Citibank Credit Card Complaint

Citibank Credit card department,

Credit line increase/decrease Arizona

I have a credit card with Home Depot. Home Depot cards are issued by/through Citibank. I have a Citibank HD credit card. For quite some time, my credit limit was $1000.00. I have never gone over the limit, and I have never paid late. Recently, I have been trying to pay my credit cards off/down to increase my - score. On or about - -, I paid the $800.00 balance on my home depot card down to $500.00, which would be 50 % of the $1000.00 limit. Immediately after crediting the payment, without notice or justification, Citibank lowered my credit limit from $1000.00 to $700.00. This action immediately changed my credit utilization from 50 % to over 80 %. It is a well known verifiable fact that credit balances over 50 % have an negative impact on credit scores. CITIBANK CLAIMS THAT A RECENT REVIEW SHOWS CERTAIN ITEMS - those items have been on my credit report for several years, even prior to when I opened my Citibank/HD card. Citibank knew of these credit items before even opening my account. Citibank gives a fake reason, claiming credit issues that it already knew about, that already existed when they opened the account and now claims that suddenly, now they matter. Citibank, and other credit cards, intentionally lower credit limits for the express malicious purpose of keeping lower income/credit persons from improving/increasing their credit score. Even if this is not the express purpose, it has the same impact. Credit companies should be expressly prohibited from lowering a credit limit that has never been late and never gone over the credit limit unless certain stringent standards are applied. Otherwise, credit companies can continue to maliciously manipulate credit scrores, thereby continuing to limit credit opportunities to high cost, low credit cards. The federal policy has been to LOOSEN credit available to consumers. Allowing credit companies to maliciously lower credit limits after a payoff allows credit companies to malicously manipulate credit scores. Why is this even legal?