Here's my word of advice to the author and anyone living this article (based on years of experience).
Get a blacklist system for your phone, block unkown and private calls (they love switching to private to catch you when you're not expecting it).
If you have no obligation to use your personal phone for work, don't. You also have no obligation or responsibility towards anyone, no matter how hard the "problem" is. Your conscience and life is being manipulated to suit the needs of others, in laymens terms, you're a doormat.
No never works, ignore always does.
I do support for just over 100 folks daily, I don't do personal favours (don't ask me to fix your personal pc, the answer is no) and my cell phone number is mine, paid with my own hard earned cash, so I won't use it to fix their issues.
ciao