Please assist -

Hi - I tried using the chat on your website - but it's not working on my side - could be my browser - anyway I can't call through. Please help me with this. I have a contract with you that is a Top Up contract. I want to end my contract and port out in 30 days. Can you change my contract to prepaid, and allow me to submit a 30day notice to end my service? Please assist me with this - email me, and I can send you a termination letter. I'd rather you assit me via email than over the phone. Many thanks for your assistance.