Luno - hiding information?

I opened a Luno account about a week ago and it was verified by them. Then when I wanted to send some cryptocurrency to a friend my account was locked so now I do not have access to my own funds. Luno is asking for personal and private information that has absolutely no bearing on my trading activities. Why was this information not requested up front when I was in the process of opening the account in the first place? They are asking for details about the third party which, according to POPI legislation, I am not permitted to share with them. Four times, I asked why they need this particular (unrelated) info but my requests for explanation is being side-stepped, and they are threatening me that they will close my account if I don't give them this info. My first foray into trading has started off with quite a negative experience with Luno.