My account was locked for deleting my own comments. I sent them a GDPR request to delete my comments. They ignored it. I posted on meta asking if they followed GDPR. It was deleted and I was banned from meta.
Actually, I don't think this is covered by GDPR, but if you are European (which is implied by the fact you invoke GPPR) you can and should file a GDPR complaint to your local DPA.