Shesha Online- Defective product

I recently ordered a sneaker from Shesha Online, however, the sneaker was defective so I returned it and wanted a refund for my purchase. However, the issue remains unresolved, as has been going on for two weeks now. Shesha have ignored by emails, from start to finish, therefore, I have had to phone support to get any assistance. I spend over half an hour each time, waiting for assistance. It has been over a week since I returned the sneaker, and I have still not received a refund. The person assisting my query promises that the matter will be resolved, however, after over a week of trying to obtain a refund, I have no sneaker or a refund.