worst customer service

I have ordered items online and 2 items were out of stock, I've been trying to contact them in regards of the refund which was supposed to take 5-7 days the refund was processed on the 5th of April to date I haven't received my money back. Yesterday I contacted them and they requested my bank statement as proof That my money is not paid back. I don't know how don't they communicate with customers we have to run after them, even the refund I had no idea I had to ask first what's the next step. I really liked the online platform but from now on no more didn't know it is this bad.