I just got the same call on my voicemail from 636-583-2503 from someone named Kelly about cutting credit card payment in half. Funny thing is, i don't have any credit cards. It's a scam - don't call them back.
Just got a call during my class, same basic voicemail as already described. Some girl named Kelly acting as if you already spoke to her, sounds like the first couple words of the voicemail got cut off. Possibly to make you think they identified you by name before the voicemail picked up?