Asking me to confirm something I don't have

I called CellC customer care this morning asking for their help as I needed an instant recharge. I've done this before and I was helped without a hassle. I spoke to a Sibongile who did a security check with me and found that on my I'd number instead of them having my I'd number there they have put only 5 digits. I asked her repeatedly where u would find those numbers cause I don't even know what that is. I asked to speak to her manager as she couldn't help me. Guess what I spoke to the manager for only 2 minutes and she hung up. What's going on. If I was previously helped with confirming all the necessary questions why am I being asked something they don't have. How am I supposed to confirm something they also don't have.