Disappointing Citi Credit Line Increase

I've been with CITI since 2014. I've been paying almost every time the full amount and never miss a due date. I don't remember the last time they give me an increase so I figure since I almost max out my limit and paid a huge amount, why not ask again. I did today but before hand I asked in a live chat, see the conversation below, how to and if it will do a hard pull on my credit.

I did the steps and asked her while doing it but at the end she Marina stopped answering. Customer service is a big deal for me and if you are going to ignore me while I ask questions, we're going to have a problem.
I'm posting this to alert everyone that no matter how great you are with your credit cards payments and you pay a huge amount everytime or one time, it's not going to help you get an increase.
"We regret that we cannot approve your request for a credit limit increase at this time.


A written explanation will be sent within 10 days. If you are enrolled in Paperless Letters, an email will be sent when this letter is available in Document Center."

I hope this will change in the future or I'm not going to be happy completely with Citi regarding credit limit increase..