It’s impossible for you to control every single piece of personally identifiable datum you produce daily.
You produce data simply by moving about in public. Interacting with any other person or organisation. Switching on your television or your microwave. Fundamentally, before you exist as a person on this planet, to
long forever after you die, data about you is processed.
That’s just how your life is in the 21st Century I’m afraid. You cannot change that fundamental fact.
Why are you obsessing about just the CRAs? You can’t have a Monzo account without the bank passing your data to the CRAs, to the company which prints and sends you your debit card, to every bank which holds an account of someone you pay money, to every shop you purchase at, and every company which runs their card POS terminal, and their bank, and Visa and Mastercard and Amex, and Google which produces the map in the app showing you where the shop was, and Apple on whose device you run your account, and Amazon which hosts Monzo’s data, and Flux which tallies up your loyalty points, and on and on and on.
GDPR is the best tool you have to protect you, and it’s pretty damn good. An example of something spectacular the EU has done for its citizens. But it’s not meant for you to control other entities holding data which identifies you, it’s designed to protect you from them misusing it.