Terrible service and lack communication

My MacBook air was sent in to determine what is wrong with it and a quotation on the repair job. My macbook has been there for 3 weeks and nobody contacts me to let me know whats happening, When i tried to follow up they couldnt pick up my laptop on their system thus said they don't have it - they later on found it and apologized only after I had to make several calls to their service centre! This is shocking as i paid R12000 for their product and this is the service I receive. I m very disappointed in the lack of service and communication. They do not seem to take interest in customer service - I spend so much on their products and this is the service I received?