AFRICAN BANK DID BRING MY CREDIT SCORE DOWN. SHOWING I AM 1 MONTH IN ARREARS.AND I AM UP TO DATE

Hi missed a payment in May 2023 due to no income commission earner. Made arrangements payment can be deducted twice end June 2023. End June 2023 they only deducted 1 payment I called in and they deducted immediately with me giving the consent from my side. I am currently in the market to buy a house. August I decided to do a Credit score check. With my disappointment my Credit Score went down reason be I owe African Bank 1 missed premium that was paid already. I normally do a balance check via What's App and Arrears show R0. Balanced +-R2600 still owing . Called their 011 Johannesburg number and call centre 0861 a few times they keep on transferring me with call cut.I don't speak to the correct people. Sending them emails and responds via their scoring system on via cell phone number and. I am just getting no assistance. I had problems with my Credit Score and fixed everything in October 2022. Everything went well and build up my credit score very well. African Bank was quickly when I app**** for small loan December 2022 for me to build up credit score. With this problem I just don't get any assistance. Please advice me what to do.I need them to rectify my credit score by the Credit Bureau. Have 5 accounts on my name and only African Bank did bring my CREDIT SCORE DOWN,,, PLEASE ANY ADVICE HOW TO TAKE THIS FUTURE BECAUSE CLEARLY AFRICAN BANK DONT CARE