NOT IN STOCK

I bought a mirror that said in stock. When I paid for the mirror I received an email saying it was out of stock till November(a month away)I asked to be refunded and this seem to be no problem at all. After waiting 2 weeks for a cheque which never came I rang the customer service who then took my bank details promising me a quick refund, another week went by with no refund. I rang again to be told that they had sent another cheque which did come after 3 days. Once I put the cheque into my bank account it bounced. I couldn't believe it, I rang again, this is now 5 weeks since promised a refund. I was promised that the money would be in my bank in 3 to 5 working days using the account details I gave them weeks ago,still no refund!! I rang again and I'm waiting on them getting back to me. Am now in week 7 of waiting for the refund. This is an absolute joke, how can a company treat its customers like this!!!