Very poor support service

I am a seller on Takealot and rely heavily on The Courier Guy to get my orders in on time. They messed up on one of my orders and there is no communication from them as to why this happened. I have spent this whole week emailing and phoning (the supervisor in Cape Town does not answer his/her cell phone). I have lost money as all my orders in this shipment were cancelled by Takealot for being late. I need to sort this out with Takealot as they may suspend my account but The Courier Guy are ignoring all my requests. This has negatively affected my business. Not impressed with their support service.