Billing and Router cancellarion

I the month of June I upgraded to Rain101 and was told that the 5g I had will be disconnected as soon as I receive the new one but that was never the case and have logged several calls I paid +-R780 in July and to my surprise when I checked my bill on the 1st of August it shows that I have to pay R1164, I phoned rain and was put on hold for over 30 minutes.I then spoke to the consultant who told me that services were provided by Rain and that I'll have to pay the whole amount (IS THIS NOT THE PREPAID SERVICE PROVIDER)? I then requested to speak to her supervisor who was too busy, I was told that they'll call me back but they never did, please note that from my understanding I have paid extra money for the month of July, Rain failed to cancel the old router even after logging calls many times,

Can the supervisor call me as soon as they are available please,

I will not be paying the extra amount again this month