Pathetic service from Fastway & their staff member, Yolandi

I'm a client of Fastway South Africa. There service is pathetic. Yolandi, whose supposed to be in charge of queries etc. is so unhelpful. She doesn't respond to any messages or calls. There's a customer that's hasn't received a parcel that left 2 weeks ago. The head office also doesn't seem to care. I need to be credited for an amount and I haven't had any feedback from Yolandi or fastway customer services. Its so frustrating.