Metrofibre - Incompetent service and not updating their accounts which results in my account being affected

MetroFibre's Finance department is extremely incompetent with updating their accounts for their clients. I have changed my account details using a different account to what I used before, on 15th August I called them and they sent me a Debit order change form to change the bank account which they will debit me from as well as the debit date, I changed my details from Capitec to FNB and debit date from 27th to 31st (last day)of every month starting August and moving forward. They sent me an email back on the same day 15th August to acknowledge receipt of my changed and signed debit order form and confirmed that my account will be updated as per what I have requested on the change of debit order form. I have made the debit order date to be 31st(last day) of Every month starting from August and to be debited from FNB account. I have since been calling starting from the 1st September to enquire why my account has not been debited on the 31st (last day)August as I am afraid that they will do what they do best - cut off my service! because their accounts are never balancing! (at most times you cannot reach them on the phone as calls gets cut off and never returned). I have followed up with emails which also have not been replied to. I sent another email this morning enquiring what the challenge is, with no response. I then followed up again with a phone call and finally got hold of them after holding on for about 25min!. They then advise me that my account is in arrears as I had a returned payment in May??? (which is not the case as I have all my payments from May until July as successfully paid and it shows on my statement.) they are now telling me that my account is in arrears and that I have an whooping amount of R728 something which is outstanding due to an unpaid debit in May!!!!???? Its September now and they are talking about a so called, and incorrect unpaid account in May, which by the way was successfully Paid, May , June, July.! (my bank statement is testimony to this!) I need this to be rectified with immediate effect, they never want to put a Supervisor on the line as their excuse is always that the Supervisor is in a meeting - this is not the first time I experience a problem with MetroFibre, and my service got disconnected due to lack of communication and not getting back to clients via email or telephone. This has happened before. I have this service for a reason and that is because I work from home and I CANNOT afford to have my service cut off and pay in double amounts only because of MetroFibre's incompetence! They need to fix their mess and treat their paying clients with respect. The one other frustration is that they are hardly ever reachable on the phone you will hold on for more than 20 minutes and only for the phone call to be cut off. They have told me today that they are debiting my account with that R728 something amount which is not correct as the current amount I owe them is R399.00 as per the contract and because I have no outstanding amount with them. My account is fully paid up and the only discrepancy is now due to my request to change my account details and debit date in August which they clearly have not updated on their system and have debited my old account which didn't have funds. They are bullies because they know that they can easily just disconnect your service and inconvenience me, their paying client, whilst I depend on the WIFI for work as I work from home. MetroFibre is supposed to be a reputable company and that is why I chose them to get my WIFI service from, but this is utterly disappointing and they need to relook their internal systems and give better service to their paying clients. I have never begged anyone this much to pay them as I have begged this company and only for them to tell me about returned debits that don't' exist. They clearly don't know what they are doing. ! I do not have peace of mind with this service provider they need to pull up their socks! I need this rectified TODAY

It is 2 days later and MetroFibre has not come back to me, nor has the Supervisor called as they have promised. My quirey as set above still remains the same.