No response after 8 months

I initially complained to ABSA regarding the interest rate on my bond account for 7 years which resulted in me overpaying ABSA R85000.00 which they subsequently corrected after a 6 month period. I then found a further discrepancy of R20000.00 which was debited to my bond account in March 2014. Since then I have been requesting an explanation and none has been forthcoming. It is absolutely amazing that when you're a couple of hundred rand short on your bond, you're bombarded by ABSA's call centre agents right through to their legal department, however, when roles are reversed it seems that ABSA couldn't really care about their customers prospering. Shocking!