No explanation of payment and cut off due to their bad service

I am very unhappy with the service I received from DSTV regarding my new subscription. Firstly I struggled almost a week to receive my decoder due to your service provider not having the correct information given to them. I let this frustration go and did not say anything but now I am very unhappy. All of the sudden my subscription is cut off and I have to pay R 900 before it can be activated again. When I phoned the helpline I spoke to a Thandisa who was very rude and had a very bad attitude. Nobody bothered to communicate with me that the subscription is paid in advance and she just said I had DSTV before so I should know or go read the terms and conditions. That is customer Service at its WORST. I read the terms & conditions now and my conclusion (as I did not get any assistance from DSTV in this regard) based on the following clause: 1.5 "Billing Period" means the monthly period between- 1.5.1 the date corresponding with the Commencement Date; and 1.5.2 the day before the same date in the next month, which is also the Monthly Due Date

“Commencement Date” means the date on which we activate your access to the Service;

My interpretation is thus that the due date is the same date the next month as stated in 1.5.2 as the Monthly Due Date.

I now have to pay for the service up to now and also the service up to the end of the month (in advance)- thus 2 payments.

According to my knowledge in the business you only pay for a service after receipt thereof. I cannot understand how I am left to interpret the terms and conditions and then I get billed double without any help or explanation. This is unacceptable.