Total disregard to customer plea

I ordered a Security Gate online. After a week of waiting they delivered the incorrect security gate. When i asked how long it would take to deliver the correct one I was told that there was no stock. When I asked for a refund so that I could purchase the gate from another store I was told that I’d have to wait for the gate to be delivered back to the original branch (which could take two days) and then a refund would be processed and I should get my money in 48 hours. Essentially I have been penalised for their incompetence. I tried speaking to their management, but that was a waste of time - they tell you they’ll get back to you and they don’t bother. In the meantime my animals and my safety is compromised