I had the same exact issue. All I can recommend is do not let up, find similar posts in this forum and reply saying you also have this issue, contact individual Dyson stories and ask for help, basically any way you can make your issue seen you are more likely to get a resolution. After 3 months of pressure, I FINALLY got a new machine. It was a hassle and very time consuming. Good luck ! 

Thanks Peter

I was very Disappointed. As I returned my unit to Dyson warehouse on July and until now (2nd of Oct) I still now yet received my exchange unit. 

I try to contact Dyson Live Chat, through Call customer service, and also email. All I get is the same respond is waiting and will get back me later. Then no more update for my case.

I would like to know how to feedback to Dyson so then it can expedite my case.

Maybe filing a complaint with FTC can help. Based on posts I have seen in this community as well on Reddit, it’s clear they have business practices are harming customers. Here is the link to file a complaint. Share how this works for you to help others in the community find a solution! And report Dyson’s bad business previews