How to get cash from credit-cards without the back-breaking 20% cash advance fee

There are numerous options for liquidating credit cards.

Plastiq

Marco Cabajo, the business credit wizard, has written an excellent article on using Plastiq to liquidate credit cards.

PayPal

I do not use PayPal for very much, but if you have 2 bank accounts connected to 2 different PayPal accounts, then you can simply send money between them using a credit card as a payment method.