Delay in Dispatching Replacement Vacuum

Hi

I had an issue with my V10, broken trigger. I contacted customer service and they agreed to replace the vacuum and to await contact from courier.  

Days passed with no email so I contacted customer service again and was told the replacement order didn't go through. It was re ordered, again days passed with no email.  Contacted them again to say that it had not been dispatched. It was made a priority with still no dispatch email.  

It has nearly been a month since I first made contact and no closer to a resolution as I keep being told to wait 24 to 48 hours. 

Can anyone advise who I can chintzy in Dyson to escalate the issue?

Thanks