Incompetence at GEMS

GEMS claims that I owe them over R19 000 for one of my dependents because I have not submitted proof that he is still a student. This figure is for the past two years. I have submitted this proof at the end of each year since 2018 but it seems the departments involved don't share correspondence and I'm made to suffer for their incompetence. I also send the same proof last week but when I enquire today I'm told they still didn't receive proof of registration with an education institution. they now threaten to terminate my dependent's membership if I don't resolve the matter by 10 November 2020