Sizwe Medical Fund issue not resolved after 3 months

I have been in communications with Sizwe Medical Fund since 1 March 2019 regarding money that is owed to my practice. I've called numerous times and sent numerous emails, but the matter has still not been resolved. All i need is for Sizwe to update and confirm the banking details sent through on 6 March 2019. The fund claims to have been trying to contact the practice, but I doubt that as we haven't been getting any calls from them in our 11 hour business day. I received an email on 4th April, 10th April and 15 May from the fund yet nothing has been resolved as apparently only 1 person can resolve this issue according to the call centre agents a speak to, who don't seem to have any authorization to do fix any issues. This issue needs to be resolved asap and Sizwe needs to step up their poor service.