Incorrect caravan cover

I ordered a canvas cover for my caravan from All Outdoor and Home, in Brackenfell Cape Town, more than a year ago. I questioned the size they offered and confirmed the make and model to them. They insisted it was the correct size. I received the cover and it was incorrect. I contacted them and they promised to replace it as soon as they got new stock. I asked if I could leave the incorrect one on so that I would have cover in the mean time, and they agreed. Not long after installing it, it started tearing on the corners because it was the wrong size. I have tried to contact them on numerous occasions since then but they ignore my mails and calls. After a year I still don't have the correct cover. Lesley is just ignoring me