Not settling hospital account in full

The member was admitted in Pretoria East Hospital for the period 22/5/2014 - 4/6/2014. An amount of R1 131.00 has not been settled and I asked for feedback on numerous occasions but none is given. This was for a PMB condition. I want a detailed explanation why this amount has not been settled, my last enquiry was made in January 2015 and I was promised feedback within 5 days!!!!