Frustrating Service!

On the 26th September I was supposed to pay my monthly premium and the debit order R149 did not go through because I didn't have funds in my account. They called and I changed my premium to the 1st of every month. 1 October they debited R169 and it went through. I think on the 6th they debited R149 and I reversed it cause I had already paid. Now I am getting emails and sms saying I owe R198, I don't know what it is for. I sent them my bank statement but they failed to assist. I am not sure if they are aware but for every debit order that bounces back there's a fee. I am now on negative because of that bouncing debit order that is made daily. Come month end I have to pay my monthly premium plus the negative amount that they are busy making on my account. I swear if this is not resolved I am going to cancel, reverse my last 3 payments and not pay that cancelation fee. This company does not take their clients seriously. I am fed up! I need an explanation.