Disappointed in service delivery from the Courier Guy

I sent a large amount of parcels from Cape Town with The Courier Guy on Wednesday the 28th of December. It was supposed to be delivered in PMB, KZN on the 31st of December as per the online quote I agreed to. However, when I tracked the parcel today (30th of December), I noticed the parcels haven't even left CPT. I tried emailing. The support lady said that my parcels will only be delivered the following week, 3rd or 4th of January. When I queried why delivery is taking so long, she said there was a delay due to a few extra parcels being added and payment for these parcels being late. Which is not true. I have a POP which shows payment I made within a few hours of collection. When I questioned this, the lady stopped replying to my emails. I then phoned. Someone put me on hold in the middle of me explaining the situation. Someone promised to phone me back 5 minutes later. He never did. In essence, I was told that it was my fault. I was supposed to pay an additional fee for delivery on a Saturday. Which was not communicated to me. This was never part of the agreement. When I asked how I can speed up the process, the one man told me I can drive through to Durban depot and pick up my parcels myself (context: Durban is over an hour away from PMB and I have too many parcels to fetch them by myself. Also, this is their job - to deliver my parcels!). There is no way to help me. I'm extremely disappointed in The Courier Guy. The staff at the support center are unhelpful. I need my parcels in time to be able to work on the 3rd. I have stethoscopes and medical equipment which are essential to perform my job. I left ample time for small delay but this is absolutely unacceptable. I would really appreciate any help (contact details, etc) to hasten the delivery.