Yes, I have asked Abra also and they basically said the same thing as Coinbase. I agree that the Bitcoin miners are the reason for my problem.
Your problem is slowly becoming one real mystery.
First thing, for anyone to have a clue what might have caused this you really need to tell us what or who are those bitcoin "miners".
Seriously, I have no clue what are you referring to.
Did you purchase or tried to purchase some miners? A cloud mining contract? Have you tried to mix those coins maybe?
You simply can't send coins to "some" miners.
If you are indeed blacklisted from 3 exchanges I wonder how have they flagged you, a simple transaction in the chain won't get you in this much trouble, I've never heard once about something like this unless you were involved in some darkweb business but at this point, you would probably write those from jail...
So, there is only one advice we can give you since its pretty obvious your ban or your ban account is useless.
Try with a bitcoin ATM. If that fails....you're cursed!!!
LE:
Wow, the fees ATMs charge near you....at least 7%..