Dyson Vacuum Attachment Lost by Service

I sent a Dyson attachment to the service center, but they lost it. They assure me a replacement will be sent when it's back in stock, but there's no clear timeline. Why should I wait for Dyson's mistake? I've been waiting over 20 business days; why can't I use the attachment I sent? It's not my problem if they don't have it in stock; I sent it to them complete, and now I'm getting it back incomplete. They can't offer more than saying my order is active. According to consumer rights, when the maximum repair time is exceeded, the customer can demand a free replacement or a refund. Therefore, due to the service exceeding the 20-business-day period, I demand a complete replacement of the product.