Double debit on the wrong date again

I would like to know why you guys have double debited me today for R807.00 when my contract suppose to be R399. As per conversation with Timmy he did mention that there was a system error and they mistakenly debited me on the 23rd Oct. Today i see R807.00 is debited off my account and also the banks charge me R100 because there are no funds available due to Telkom debiting me on the incorrect day. Until today no one has got back to me with feedback. I want to cancel my contact and advise all my family members to do so as well because the service is terrible. I never had the problem with Vodacom. Who is going to pay for my bank charges and why did you guys double debit my account????? I want feedback ASAP.....