Dissatisfied customer

I’m being treated unfairly by specsavers after I selected the Eye Care Package for R899, which included an eye test, a selected frame and single vision lenses which was paid for through my medical aid. After receiving them I then discovered that there was a problem with the lenses, as I could not see properly through the spectacles. I even mentioned this when I came to collect them during the fittings. I raised my concern with few days of receiving them expressing my disappointment. They called me in redo the test only they expect me to pay R850 which I queried which they told me I will not have to pay. Only when the test was done they informed that I will need to pay. You don’t misinform clients like that after you didn’t deliver according to their needs.