Horrible experience with Vumatel. 16months after installation they said i didnt pay installion

Very Disappointed. I was a member with vumatel an Rocketnet last year. I was a happy client for 5 months. I then left the country. I made sure I paid a penalty for leaving Rocketnet before ^months. After 18 months Vumatel is saying I did not pay the installation fee??? How can I use the service for 5 months without any mails or phonecalls. This was 16 months ago. Now I receive a call from Vumatel to say I didn't pay installation. I Closed my bank account that I were using that time. So I cant send any proof of payment. I am not using the same email address so I don't have any proof what was signed for and the amount. Who can really remember what they paid for 16 months ago????? My credit record is 100%. I never pay late or skip payment. When I left the country I paid early breach of contract penalties like dstv, Rocketnet, My flat etc. But I made sure I paid the penalties because I knew I am coming back one day and don't wont to have a bad name. Vumatel phoned me last week. I have send emails, phoned them every day and left messages for a manager to phone me but nothing happens. I am waisting my time and money.

Please Vumatel. Sort this out.