Wrong debit date and Amount why ?

I have an issue with Telkom on debiting me on a wrong date - for the month of October I had spoke to a consultant who was very rude to me prior before debit date and I was debited on the 26th - FNB charged me R105 for a bounce debit - on the 27th Oct I took a new contract again debit date was changed to last day of the month - on the 15th I paid R400 at Game to telkom bill - Telkom debited me R935.01 on the 26th of Novemeber again - why ??? who is suppose to pay again for the charges - the money in my account was not for telkom - what happened to the R400 paid - and I was charged once off subcription of R205 for what I dont know - I want my refund because i have a credit balance of R400- telkom consultatnt are very rude and its even hard to get them on the line - i was advised the 30th is the only suitable date for a debit - statement said to be debited on the 30th why on the 26th ?