Line suspended

Before I renewed the contracts the last time I ensured I would be able to pay my account on the 15th of each month. Some months it is fine. By the 5th of every month we get an sms from Vodacom saying that if you're going to pay in the next 7 days you have to reply which I do. Some months however this doesn't work and they cut my lines despite my arrangement for the 15th. This month we only received the message yesterday yet yesterday afternoon all my lines were cut. I called the call center numerous occasions yesterday, they told me if I agree to a debit order it will solve the problem, which I did. After this they said they're still not switching on the line until I pay the outstanding amount even though I assured them I'll pay them on the 15th like I do every month. They then told me to contact collections which I did this morning, I was informed that they're sending the request to unblock the line this morning. When I called again now they told me again they're not connecting the lines until I do the payment. Maria Sangweni actually put the phone down in my ear!! Every month I pay the amount which is SMS'd to me yet they tell me I'm behind??