> Don't publish your number beside the 5 people (bank, accountant etc...) you are willing to receive call from.
Unfortunately this doesn't work. If the number itself has ever been used before (it has), it's already on a bunch of lists. Many banks and credit card providers will also share it with marketers.
It's very different in the US. Many banks/credit cards will share your contact info for marketing by default and require an explicit (and often burdensome) opt-out.
