This call was seeking donations for Minda Inc.
Not sure if it's actually the charity or a fund-raising business contracted by them.

This number and others similar keep ringing me. When I answer they hang up.

I think it's the UNHCR, like maybe it's for the funding details if you've subscribed earlier.

When I rang back the message was 'thanks for calling Mondeal (sp??) - we support a range of charities....."

I was getting calls from the Guide Dogs previously. Might be them

I called back number (08) 7099 9638 rang once then gets disconnected automatically.

Rang my no. Twice. I don't answer.