Unpaid charge

The behind of September I called to change my bank details for my debit order set for the 25th of each month. I was told to avoid the unpaid charge I need to pay 10 days before my pay day... It’s very unlikely for me to have that to have that amount of money during that time of the month however I managed to do it as I didn’t want to sit with disputing a bill since I’ve had in numerous challenges with Telkom crediting me for their mess ups so I didn’t want to sit with having to call in over and over. September bill paid all was well until October on my pay day they never deducted then Monday I called to enquiry, now to get through to Telkom alone is one hell of a ridiculous mission never mind that I’m just nevermindedly told that that unfortunately the bank details weren’t updated but there were notes to say I called in BUT I now have to wait to be charged for the unpaid before I query it and I know Telkom doesn’t refund they just do credits back into your account. So because of this I need to now include in my budget an unpaid charge which may seem not much but it’s not something I would want to sit with in the first place. Because of this one mishap I get to call in when I’m free I was only able to call back Beginning November so trying to update my bank details now is also an issue as the system wasn’t allowing it. I was so long on the call I had to drop as I had to get back to work. I was told I can get a credit for the unpaid as it was their fault however calling back 10times and each consultant with their own understanding wasn’t understanding what I was asking. Now because of this I’m still left with an unpaid charge I will yet again be charged in November for notifying them too late about my bank details and I now sit with an add on of charges for Telkom’s mess up. I’m patiently waiting for someone to contact if this matter is not resolved accordingly I will take it further with the ombudsman as I am now fed up with telkom