Failure to refund payment

I made a payment to SHEIN Africa on 7 th July through ozow and cause of network issues the page reloaded before the payment could be processed I’ve been in constant contact with my bank and SHEIN and it’s been a hassle because SHEIN doesn’t want to respond to my emails sending them proof of payment and a payment reference , Its so frustrating because we always use SHEIN but this isn’t acceptable