Appalling service / inability to get a response / unjustifiably still holding our deposit!

We cancelled our lease with Regus Offices in Durban over a year ago. We are still waiting to get a refund of our deposit. Firstly it seems impossible to get to speak to anyone directly regarding the refund query. Secondly, despite having written letters to them and changing our contact person on their system as requested by Regus, we seem unable to get a response or a refund. Based on this experience i would never recommend doing business with them.