Service not delivered

Takealot sells dishwasher installation vouchers from a company called 4-Sure. (See 4-Sure review.) The company couldn't deliver the installation I bought and I'm not able to get a refund. I've had to hire someone else to install for me, at my own cost. Disappointing as I've consistently had good service from Takealot but they seem ill-equipped to deal with this complaint and it's become expensive to solve - financially and in terms of wasted time.