Item not as described and does not work (windows 7 key)

[amaris-blue]

Hi 
Bought a windows 7 key using buy it now and it was described as being sent instantly which it was not, it was sent to me over 12 hrs later
Also the key does not work, when trying to use it on the Microsoft site it comes up with error message stating

"Error

The product key you've entered appears to be for software which was pre-installed by the device manufacturer. Please contact the device manufacturer for software recovery options." 


Does anyone know how to get money back for this item and what is best way to go about it ? 
I have tried contacting the seller already twice so far and no reply 

Thanks in advance 

[arkwebus]

Such digital thingss are not allowed on eBay and I am afraid there is no cover under the MBG.  Your only hope is to get on to the seller [and in view of your comments ...]

@amaris-blue