It took less then 1000 people to made them do that, it's possible to reverse it:

Mastercard (US): 1-800-627-8372
Mastercard (Int.): +1-636-722-7111
Visa (US + Can): 1 800 847 2911
Visa (AUS): 1 800 125 440
PayPal: +44-0203-901-7000

In case you are not sure what to say:
>Hello, my name is _____, and I would like to file a complaint. I find it troubling that Mastercard is blocking content on (the platforms you use) and making it difficult for me to make legal purchases. I am going to stop using Mastercard if this isn’t rescinded and fixed.

It took less then 1000 people to made them do that, it's possible to reverse it:

Mastercard (US): 1-800-627-8372
Mastercard (Int.): +1-636-722-7111
Visa (US + Can): 1 800 847 2911
Visa (AUS): 1 800 125 440
PayPal: +44-0203-901-7000