Refusing to refund

I erroneously paid Hypa for reconnection instead of SADV in January after my line was closed in December. I asked for a refund since then it hasn't been paid. I have asked SADV to release my address which they did so I can just continue with Hypa. Now Hypa is not refunding me and I can't get reconnection either as I am still waiting for my refund. Their service is so damn poor. The fact that I can't telephone them the communication is just via WhatsApp is not really helping because they live you hanging without a resolution