Failure to take a debit order becomes MY problem!

We bought a new decoder last month. Towards the end of the month, I started getting snotty sms messages about paying my account. Since I've always paid by debit order, I ignored them for a while, before eventually contacting them via Facebook, where they confirmed the debit order exists, and said the constant messages were a "system error". Checking my spam box today, there are more snotty messages demanding payment, so I checked my account and saw the debit order hadn't gone off. Asked the Facebook people to investigate. Turns out, DSTV decided - without consultation or permission - to change my payment method to "cash", so they didn't put the debit order through. FB people tell me to add it again, but when I log in, there it is on the system, exactly as it has always been. The only action/option available is "cancel". So what exactly am I supposed to do? You have my details, and authorisation to debit, but apparently you'd rather have a p****d off customer than the money. The last time this happened - and yes, it has happened before - they cancelled my subscription and charged a reconnection fee, all because their accounts department is apparently too *********** to process a debit order.

So DSTV, do me a favour: process the f*****g debit order, and while you're at it, explain to me how it is that a customer's preferred payment option is changed by somebody other than the customer, without any written permission or proof of agreement to this change.