What a disgrace

I have requested Ampath accounts department in Pretoria on 3 August via email to furnish me with an amended invoice number CPZ67430 to enable me to receive a refund from my medical aid. No response was received and I attempted to phone them on 11 August without anybody answering. On 12 August after 4 attempts someone eventually answered and informed me that their email department has as yet not answered any emails from 3 August and onward. Can anyone contact me urgently to resolve this matter.