Horrible Service

I was quoted R29 000 for a slab. I informed them of the bigger garage on the day of the transfer, 6/11/15. They were suppose to physically measure the erected walls, they didn't. I had to complain first, when I enquired about the progress of the order, for them to come and take measurements. After that, they kept quiet until I phoned them on 27/11/2015 to ask about the status - 5 working days away from the end of their turn around time (TAT). Annesta told me it was scheduled the next Fri, 4/12/15- last day of TAT. I didn't complain as it is what they promised. When I phoned on the 4th to enquire, I was sent around. No delivery made. Monday, 6th I phoned to enquire again I sent around and not allowed to speak to the manager. At lunchtime I received an email from the company saying I must pay R9000 extra as the price has changed. Their TAT is over and they only inform me now after their TAT that I need to pay extra. I was suppose to be informed as early as possible so I can make up my mind whether I continue with them or approach another merchant. They are not releasing my order without the money. I have email correspondence to back up my dissatisfaction.