Lack of response to legitimate complaint

I lodged a complaint with SAA about missing a connection in Johannesburg due to my flight from Ghana being delayed (Also an SAA flight). I was two minutes later than the advertised gate closing time and had been promised it would remain open for me. I received a response from SAA on the 5th September with reference number ********** 28521 and was told that my complaint would be dealt with in 10 working days. I received a second communication from SAA on the 11th September advising me of the persons name that would deal with my complaint. I wrote to SAA on 21st September reminding SAA that 12 working days had lapsed and that no response had been forthcoming. It seems that SAA have a problem communicating with their customers and correcting their mistakes.