Same here. I enjoyed getting the calls. "Hello, is _______there?" "Yes, this is he" Hung up! Ha! they didn't even ask for money. So I called back and they said, "Please hold for the next available agent." Ha Ha
Citi Cards do credit cards for a lot of major stores. My company has two: one through Office Depot and one through Home Depot, and I have a personal one for Sears (which is what brought me to this page--got a call this morning from this number, assuming it's because I missed a payment last month).
My cell phone (and a lot of the newer Androids these days) have an option to send any certain number "straight to voicemail" when they call. I saved this number and a few others to my contacts so I could utilize this function--I highly recommend it to avoid the disturbance of repeated calls, whether you owe Citi or not.