I keep getting those pre-recorded calls in Mandarin calling my home phone and cell phone. One time, they even called my cell phone twice. If i don't pick up, it will go to my voicemail. I also can't block them because every time it is different.
I know the pain ☹️, these guys aren't even above leaving voicemails and filling up the mailbox 😕. I get at least 4-5 calls on my cellphone alone everyday. I do make it a point to block the number however such calls can be difficult to trace especially when spoofing Apps are involved.
I would just recommend you to be extra diligent about protecting your information like a phone number especially on the Internet.