Poor service delivery

This is something I don't like doing but after exhausting all my airtime and avenues I'm left with no alternative option. We have been trying since the beginning of August to resolve a problem with Discovery Bank but to no avail. We never informed about the migration of our credit card and that the payment credentials have changed, as such we made the payment as we've been paying for years. As soon as we realized that there is a problem we started to follow up via email and phoning them almost every second day. For weeks we achieved nothing. We forwarded the proof of payment almost 4 times but achieving nothing. At the end of August we spoke to one of the Managers who assisted us to at least explain what the problem was. We were advised that the reference number used for payment is not collated with the account as such they had to look for the payment and will then allocate the payment. Again we had to phone to follow up - we were then advised that we need to submit a confirmation letter from the account the payment was made. We emailed it minutes after the telephonic discussion. At least someone phoned us a few days after to confirm receipt of the letter and confirmed that the payment will be allocated within a few days and that we will receive a sms to confirm this. By the time of this review it still not done (almost a week again). Yesterday we again emailed them a request to have this done by close of business yesterday failing which we submit this review. We had a good relationship with Discovery for years and do we reiterate that this is not what we want to do, but if it means that this is the only way to get this sorted then we have to. The lack of feedback and action is highly frustrating. We already made the payment due for this month but are still struggling to sort out the previous month's payment. If we miss a payment we as clients are threatened and handed over - what do we have to protect us.