Inconsistent refund process

I bought a 2 piece for my daughter and on the day of delivery we realized that the picture on the website is not the same as what we had in mind and so we immediately requested for a refund and the request went through. Since the request for return was accepted on their website we decided to buy a replacement immediately after wards. Following day after driver had collected the set from us we saw an email that the refund was rejected. They accepted my return and made me think I could replace it and now i have spend double the money and only wanted one unit. If it was reject from the requested stage then I wouldn't have ordered the replacement. Now you sitting with two payments and have collected the first set but are refusing to refund me for it. You have been sitting with that set for over a month now with no refund received and not knowing were this unit has been in the last month. I would please like my refund to be processed.