Frogfoot, get a clue

So I have been trying to get my line released from the previous tenant of my flat for a month and a half now.

Turns out that Frogfoot won't give it to my service provider until the current ISP releases it. I have given proof of address and a photo of the ONT box but apparently it doesn't matter that someone else lives here now. I know the ISP that being useless and won't release is Vodacom but it is absolutely stupid that frogfoot can't just take back their line.