Missing Certificates

I started my studies in 2016 for NDip Mech Eng and left Damelin in 2018 after completing my N5 to go study at another institute to do my N6 online. Up until now I have struggled to get help from Damelin Centurion to get my N4 and N5 certificates I have contacted them and visited numerous times but nothing happens. It's been 3 years since I completed N4 and 2 years since I completed N5 and I haven't heard a peep. I can't show my achievements to my employer and it might become a problem. I don't know what to do or who else to contact to query about obtaining my certificates.