Appalling service

In March this year I bought a Sunbeam blender at Hifi corporation. At the end of September it stopped working and I returned it. I have just received an email from Domenique Thomas stating that " the blender was bought in March and I only returned it in October" as if I should've returned it earlier. Now she is saying the blender fell and they won't refund me. The blender never fell, it just stopped working. What infuriates me is the fact that it is still within its 12 month guarantee and I feel something should be done by Hifi.