Delivered damaged display card, etc.

I made the mistake to buy a computer with relevant components from Ask Bart Developers sometime in July of 2014. Goods were delivered but there was a problem with the display card from the start. I returned the display card and Bart Pretorius undertook to get it replaced. After many phone calls the reply came back that the supplier don't have the card in stock they will have to order a new one, and as it happened they just had one on back order which would arrive the end of the following week. We waited patiently for the card but when the time came to deliver the card again wasn't available but they requested if I pay in more money they will deliver a better card. We paid in the money and then was notified by Bart Pretorius that they expect delivery of the card the following month. I was under the impression if I paid the money I would get the card, but it was on order. A week or so later again there was a problem and I had to pay money in again to get an even better card. Needless to say approximately 7 months later after spending more money on the display card than you would for a brand new PC I still don't have the display card. Be careful of this one. Loads of promises....