Bad Service Service SETA

Bad service, they don't answer calls, emails. I did a learnership in 2016/2017 been waiting for my certificate. Call them no answer. sent email reply later with different answers (from they can find my details, they will reprint certificate, sent all the documents they request), till today haven't received my certificate. Where can I escalate their bad service. Did attend and submitted all the assessment. my time doing. Know they are refusing my certificate.