As an individual, you have the right to access your data and ask to remove it. But, actually, how will you know that they are really removing your data and not keeping them in some backup server?
The only way to discover is if the company suffer some data breach and you find your information there?
Thanks a lot in advance!
You don’t. But it is illegal for them to keep the data* of an individual that has rightfully requested for their data to be deleted. You just have to trust that they are following the law – same as we do with most things in society.
*exceptions apply, e.g. this and this.
It’s just legislation. That means that if somebody is doing something deemed illegal by it, the legislation itself will not outright stop it. It might however discourage or disincentivize that particular action (mostly depending on how strongly it is enforced). Nothing particular about GDPR, though, just how laws work.