I've tried using the GDPR rights, it does not work, they won't extract anything, just scribble in a mail "yea, we have so and so on you" but won't actually give

I've tried using the GDPR rights, it does not work, they won't extract anything, just scribble in a mail "yea, we have so and so on you" but won't actually give you any actual data containing any particular detail.