Here’s a short script: “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 I am going to stop using Mastercard if this isn’t rescinded and fixed."
Maybe we could find out. 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