3 months of silence

I have been trying for the past 4 months to rectify my Absa rewards. The first month i realised i earned much much lower as usual and reported it, it was rectified and my "tier" was also fixed, but the month after that, August 2017, the exact same issue occurred. I then again raised the issue but with no success, 3 months later my rewards is still not fixed and the difference of calculated reward on my actual rewards refunded as promised. I phoned numerous times and have a reference number with no luck. Currently it shows that i am on Tier 2 and only earn 0.30% of my purchases on my debit card on normal transactions and 5% on my credit card that i use for my petrol cost. According to previous conversations with the Absa Reward support i should be on tier 5, that is 1% on my debit and 15% on fuel. I am feeling betrayed by my own bank because empty promises is being made and nothing happens to rectify the issue.