Refusal of refund

I bought a pair of black shoes at Woolies on Saturday the 02/09/17. When i wore them at church that evening i relised they were big (size 6) although i wear size 6 but that one was strangely big. I went to my car outside wearing them to get other shoes to wear. I went baxk to Woolies today on Monday the 04/09/17 returning the shoes, the cashier told me that they cannot accept them as they are not in a sellable condition. I explained what happened and she could see that the shoes are not damaged at all. Now they are refusing to give me my money. I left the shoes with them becausei cannot wear rhem but i still need my money. Please help me to get my R399.00 nack. Thank you. Primrose Puling ********** 559