Disappointed client over a R20 light bulb

I bought a light bulb from this company which blew when it was switched on. It didn't cross my mind that the company would not replace it as I feel it is the right thing do do from a customer relations point of view. However, there is some small print on the receipt that says that no light bulbs will be exchanged. While this company is fully within their rights to refuse me a replacement, I went away feeling that for the sake of R20, they could have retained a happy client. I had to look for another supplier to buy the list of electrical items that I still needed to purchase!