Bad Service from NSFAS

I have been waiting for my Refund Nd Zero balance letter but Dy r no longer replying to my Emails I have send emails more than once.And I thought Maybe m sending to wrong e-mail then I ask a friend to send them email to ask about her settlement amount they responded very quickly to her.I am disappointed with NSFAS coz I was responsible Nd pay my account Nd m not being assisted