I did a charge back to NAB for similar reasons - poor delivery of RATs and NAB ignored it. Called them a month later and they couldn't find my report but weirdly
did have my reference number. So I reported it again. Nothing. Called them up again and they knew nothing, again, and when I tried to escalate it that section said they could do nothing and put me back to the original number. So I reported NAB to the ombudsman. Two days later I received an email from NAB asking for more details re the Jan claim (invoice etc). I simply flicked them the same email docs I'd sent them two weeks earlier.
Just now I received an email from the company I'd bought them from and said they were processing my refund. Except NAB have already completed the charge back. It was for 50 RATS so $495. But the company was so dishonest and NAB didn't do themselves any favours either. It was a Business Credit Card and given the business account is extremely in the Black they should have acted. Hope the ombudsman fines them.