Refusal to fix longlasting issue

Since October, I am not getting cashbacks for a specific service, meaning I have missed out on over R600 which is owed to me. I have raised this with them dozens of times, via email, via whatsapp, via phone, and I never get further than "we are consulting with internal stakeholders".

Now they have stopped responding to any query I send to follow up. They respond to other queries so this is deliberate. If an issue on a paid service takes half a year to resolve, the least they could do is explain where the fault lies, and indicate why it is taking this long.

I have jumped through hoops for months, and am now again forced to resort to Hellopeter with them because it's the only way for them to respond to me.