Download link all over the place and not functioning!

So my users are having all sorts of problems with the latest update. The latest email for downloadable content appears like this:

Thank You,XXX XXX
save the information bellow for your records.
Total payment:2.95
Transaction number:XXXXXXXX
If you have any question about your order please contact me at:[email protected]
Downloads
Downloads
Downloads
o DSC_6159
Downloads
 DSC_6159

The 2 links for the same file attempt to go to:

http://phototaylor.co.uk/wp-content/plugins/image-store/admindownload.php?&img=97e8527f220&sz=JPG%20file&c=color

There’s a missing forward slash between admin and download, manually adding this in just returns a white screen.

Could you have a look to see if its just my configuration that’s gone wrong over the multiple updates?