SARS is sending letters of demand despite my payment history and no way to dispute this from abroad

I am writing this out of frustration, not to make excuses, but because I feel like there is genuinely no way to resolve this while living outside South Africa.

I fell behind on tax payments after a long period of unemployment in South Africa, and shortly after that I moved abroad for work. Once I was settled, I set up a payment plan and started paying consistently. In July I missed one payment a mistake, I mistakenly missed a zero, not a refusal to pay and I corrected it immediately by paying double in August to bring the account current. I have since made my payment for September as well. Out of a total debt of R12,000, I am now more than halfway paid off.

Despite this, SARS is now sending letters of demand as if no payments have been made at all. When I call, I get moved between agents with no real resolution, and there is no dispute or query option on the website that actually applies to this situation. As someone living abroad, every one of these calls is expensive, and I'm also dealing with tax obligations in the country I currently live in. Trying to sort out one missed payment, that I already corrected, is taking up time and money I genuinely don't have to spare right now.

I understand SARS has processes to follow, but there needs to be a way for South Africans abroad to actually communicate and resolve issues like this without it costing a fortune in international calls or being sent threatening letters over one missed month that was already remedied.

If anyone knows of a working email address, online dispute channel, or SARS contact that actually deals with query resolution for expats, I would really appreciate the help.