On Saturday I bought a t-shirt (14.95) for my son which was too small for him. I brought it back to the shop yesterday, complete with tags & receipt and asked for a bigger size, which they didn't have. In fact they had no more t-shirts left in the shop. I asked for a refund but was told I wasn't entitled to one. The Assistant insisted on giving me a credit note, which I didn't want as they've very little stock in the shop. I wasn't sure of my entitlements and eventually accepted the credit note (unwillingly). Could anybody let me know of my rights on this one? Thanks.