Account Chaos at Multichoice

We were offered an upgrade to the Explorer Ultra at a lower premium than our old Explorer decoder. The new decoder arrived and was installed on 22nd July, however the installer said he couldn't activate it. Eventually after 40 minutes of my cellphone time I managed to get the new decoder activated. A few days later we were disconnected and a massage said that we must pay a new premium, however our premium was paid up for July. After another 30 minute cell phone call I managed to get the service running with the promise that this error wouldn't happen again. However today we are disconnected and a message say that we have to pay R1300. We phoned Multichoice and told them to call us back, as I was not going to use my phone time to clear up their account problems. I would also like to escalate this problem to a manager for explanations. Our old Explorer decoder was working fine with the subscription we paid and we didn't request the upgrade until someone phoned us for the free upgrade and installation.