Answered the call - no response then hung up.
I returned the call an hour later - answered with ‘Hi (my name) I hope you remembered me we spoke recently regarding solar panels and you told me that you had solar panels on your roof.
Yes one of them had rang me about a week ago. I advised them. I did not have a roof to have solar panels on and to please remove my details from their calling list.

I received a message that this number had called and did not leave a message. My phone did not ring! Number is now blocked on my phone.