Nsfas is not reachable

I have been trying to get hold of nsfas on their number it always says it is congested. I tried emailing them several times they don’t get back to me. I was a student at walter sisulu university and I was funded by Nsfas the university sent debt collectors and say I owe close to 100k I wanted to call Nsfas to find out from them how much did they pay the university.