In a different post, I let the community know I got a $4.5 CLI about 20 days ago and was doing the happy dance. I tried at 6 months, then again some time later and was denied both times and gave up. I only had the card a little over a year.
Then I get a call from them on a Saturday about a week ago (missed the call) and said for me to call weekdays and it was not a solicitation call. I said - o' crap, there goes my CLI.
So I call and they said in response to my recent request for a CLI, they will approve me for $2K. FIrst I didn't request a CLI (not in the last 4 or 6 months anyway).
Then I thought they were saying I wont get the full $4.5 they already gave me and were already CLD me. I didn't say a word because I waited 20 years to get one of these cards and would treat it well either way.
Well, it was neither reason, they volunteered to give me another $2K without me even asking. I got 2 CLI in less than a week and didn't ask for either one. My CR still shows my original CL and will now show a $6K increase when it updates this month.
I think that is decent and would never believe that would happen to me. What normally happens to me is the way Citi, BOA (and now Target) treat me, they want to throw me away.
I 
Discover.
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Congrats!! 
Did you already verify the CLI?