Rain Mobile network - stay away

I never thought I would ever write a public comment to express my disgusts in a company, but I tried my best to get this solved between us on a civil manner. First of all getting hold of them is near impossible. I was issued about 10 tickets that they will get back to me (with reference numbers). By spending how many hours trying to get them on the telephone I was transferred - nobody answered, The other time I was told they cant help me. I had a Rain subscription for a wi-fi. First two months R699 per month. You have to sign a debit order so they full control of collecting the money. Next two months price increased to R999 per month. I then cancelled. Next month R999 were deducted which is fair, and then an amount of R354.48 was deducted. I thought that would be the end. a year later I received notification that I was handed over to the lawyers because I owe then R354.48. I logged into the account and in their statement history it showed that they collected R354.48. Nobody during the year send any form of notification than an amount is outstanding. I just got the letter that I am handed over. I tried everything to find out what the R354.48 was for, and why has it been charged twice? The excuse I got is their system cant go back so far and that they cant give me an answer. I asked them can they at least explained why a subscription would go from R999 to R354.48 and then another R354.48? Again they cant explain. My question, if they said I owe them a million rand but they cant say what it was for, am I still liable to pay that based on the fact that that they don't know but in any case handed me over for a million. This is just unacceptable. I did pay the R354.48 still not knowing what it was for. My issue is my credit rating are negatively impacted for something they cant give me an answer for.