I’m trying to get ahold of a debt collector to try and pay a bill or settle and they won’t answer the phone.

Yeah the title pretty much says it. I’m trying to get my credit score better by just paying off debt one at a time. This is the last one I want to pay off. I’ve called a few times, it won’t let me connect to an actual person and always ends up hanging up. There’s no online services or anything. Does anyone have advice on what I should do with that one? I know debt laws are different in some states but anything would help at this point. This feels crazy that I’m the one chasing them to pay.