Called twice in a week. No messages were left

this one rings me and hangs up before I can answer totally annoying

I never answer but when I call back - they are Clever Contacts, a fundraising place for charities. Basically they want money.

unsolicited call.

I called back and there was an automated message that if you received a call from this number it's from a company called Clever Contacts on behalf of a charity.

Calls but doesn't leave a voicemail.

Constantly phoning and not leaving a message. (Phone calls can be of the afternoon, or dinner time)

RSPCA fundraising

Thanks for calling and hanging up in my face. Not nice. :(
I have a lot of worries. Please be kind. !!!!