refusing to refund me

I bought 3 pairs of shoes in separate orders unfortunately all 3 shoes were small I returned all 3 in a good condition they were collected on the 23 July 2019 and after I did not receive ant feed back form runway sale I called them on 06 August 2019 and the lady apologized and they refunded me incorrectly I wanted the money t be credited back to my card not credit store . don't know why they don't want to refund me back . you cant force me to buy please send my money back to my card