Damaged wardrobe

I bought a wardrobe at homechoice on account.they charged me a R100.00 for the guy who assembled it.the wardrobe was delivered and guys dd not install it level ,the others door is higher than others.also while installing they drop one of the door on the floor of which it was a liitle bit damaged at the corner.so they guys said homechoice will fix it dont worry.now i called them to ask when will they fix this wardrobe.and they said there is no way coz i assembled it of which i dd not assemble they assemble.why would they charge me R100.00 for assemble at the first time if i will assemble myself.