TL;DR - I'm fresh starting with a new phone, a new cellular service, and Graphene OS. I'll be getting a new number too but need to keep the old "dirty" number because too many family and friends are attached to it. I'm not interested in paying for two separate phone plans just to maintain the old number. What's the best suggestion for keeping the old number but fire walling it?
More detail - two family members made some bad decisions over the past year and now my phone number is compromised. I've been inundated with robocalls and at one point my calls were being rerouted, for example if I attempted to call my bank, the number was rerouted to a salon or a BBQ restaurant. I'm pretty certain that at some point, my calls were also being surveilled but can't prove it for sure.
One of these family members continues to indulge in risky behavior but I can't "cut them off". Since they already screwed up my last number I just want to maintain that particular # as a method of contact for them, but I also want to firewall that number off somehow so it doesn’t contaminate my new secure phone set up. What would this forum recommend? Porting it to a VOIP service? All suggestions are appreciated.