Problems with Backorders for Dyson Vacuum Head Replacement

I bought a new head for my broken Dyson vacuum, and they said they'll send it in three days. It's been two days and there's still no sign of it. I called their customer service, and they told me they would take care of it right away, but I still haven't heard back from them. I called again, and this time they said they didn't have the product in stock. They promised to send it to me once it becomes available. We spent a lot of money on this product, and when we purchased it, they promised us that there wouldn't be any problems. But when issues come up, they put the blame on suppliers from other countries. They keep making excuses like saying they need to update their stock. I can't live in a messy house because I have asthma. I don't know when they will update their stock. I don't care where they find it, I just really need that vacuum head replaced as soon as possible.