Incorrect refund

I ordered items on shein on the 24th January 2025 and found a msg saying I need to do a refund because 2 items were out of stock I dd the refund of tht 2 items and only received 1 payment within 48hrs and I'm left with the second one which is 573 I send them a msg the keep telling me I need to consult my banker at the bank they send me back to shein so I texted them again they said I should wait 7/20 business days today is the 28th business day I haven't received my money. I send them my bank statement but stil nothing