It's an unlikely scenario - but block your domain, block bank transfers (not for small offenses, though). "Ask" any EU based payment providers (pretty much all have offices in the EU) to stop servicing you. You can use crypto currencies and the like but the inconvenience is there.

Then probably (or your employees) would not like to visit the countries there, etc.

Technically you should not be selling electronic services in the EU w/o EU VAT, so that already is sort of a breach... but no one chases so small fish.