Just called my number and didn't leave a message

Called two of my land line phones (in different names in different cities, forwarded to cell phones) within minutes, no messages.  Both said "name not found", and that's NOT what my phones say for unknown callers....Now blocked.  

Got repeated calls from them in the last few hours. Each hangup resulted in the phone ringing again almost immediately, so an auto-dialer is definitely being used. After the sixth call, someone finally said something. Female voice, light valley girl type accent, if that make sense. Said something about me owing money, requested payment, but wouldn't state anything else. Hung up, blocked number.

10 minutes later, she called again from this number:
(209) 649‑880‍0
Blocked that number too.
Hasn't attempted to contact me further.

I also received a call from this number.  I didn't answer it.  The caller didn't leave a message on the answering machine.  I d call it back to see who they were.  I got a recording saying "Your call can not complete as dialed, please check your again number again"

Called on a Sunday - and naturally, no message left so I do not know the nature of their scam.  Area code 209 is legitimate however the prefix of 024 does seem a bit suspicious.