3 Months and system still not functioning properly

Their system has been on the fritz since December 2020. In January they lost ALL my bank feeds dating back to 2016. I requested support and received a message that they are working on it, but after it was 'recovered', my banking still showed an overdraft of over R30 000 (and I do not have an overdraft facility). Trying to work on the system is a nightmare, constantly being met by their "We are sorry to have to tell you this, but you have just experienced an error." page ( I now call their 'screen of death'). I sent a complaint again in February and requested a refund for the weeks I was unable to effectively (if at all) use their system, and received no response. We're now at the end of March and today while still trying to find & fix discrepancies, I once again keep getting the 'screen of death'.