Caller: Credit Corp

A debt collector.

Rang and said I have options, for what I dont know

Would not divulge who they were, just kept wanting me to say ‘yes’ + that it was ‘a sensitive topic’ ... I ended up hanging up on them

Caller: I don't know

I received two calls from this number on my work phone. As I don't share that number, I presume it's a scam.

Go to phone box and call them. When they answer, don't hang up put the phone on the top of the unit then leave.
Do it a few times. Just listening to them having a stroke after you've done it 3 or 4 times is worth every cent.

Arseholes spam

I called back number (02) 8024 9460 rang once then gets disconnected automatically.

Calls and hangs up. Spamming everyday.

I called back number (02) 8024 9460 spoke to a woman who said I've reached a switchboard but did not say for what company.