They have called me for the past 3 weeks always on a Sunday morning, No message left so now blocked

This number has been calling me repeatedly on evenings and weekends. I refuse to pick up and they wouldn't leave any message. I have blocked the caller.

Same as Sam, this number called me around 4.30pm (I was working so couldn't answer) on 3 May. When I rang back from a landline, a message stated that the number 'wasn't in service'.