Totally suss call. I answered, there was a suspicious silence for several seconds, then some weird sound (?), then they hung up. And when I called straight back (within 3 secs) it went straight to a voicemail: 'The party you have called is not available. Please leave your message.' And if it were a legit person/company they'd say their name and the company name in their voice mail. And I called back so quickly that obviously the phone was in their hand, they just ignored the call when they saw it was me ringing back. Well suss.

as above - typical spammer / junk call

They called but hung up quickly before I could answer. I called back and it went straight to a voicemail: 'The party you have called is not available. Please leave your message.'