Invoice enquiry

We send A4 documents about 3 pages to a client Fedex 1 service..<br> <br> December 2014 bill R131.48<br> April 2015 bill R126.47<br> September 2015 bill R545.26<br> <br> We request an explanation on 8 October 2015 - Carina van der Ryst after 2 weeks of no reply I phoned and asked for another name and email, I got Thobile Manana's email address I emailed 27 October 2015 and asked for assistance, on 29 October 2015 I phoned and send a mail to Leigh Taylor, she opened and read the mail I have the proof, I phoned again and requested another email address and received [Email Removed] this lady Aisha Mahomed just forwarded the mail to Thobile Manana, still received no answer.<br> <br> This is not acceptable.<br> <br> Please can someone tell me how I can get the answer to my inquiry.<br> <br> Thank you<br>