Unique downloads count per user problem

I’ve a client that has set a maximum of 40 allowed downloads for the s2m member. If the member selects 6 items in the basket to download, it is only counting this as 1 download. How to resolve this? How do you count the total number of unique file downloads? Or is this approach incorrect?

I see an API function to count file downloads by the current user: $s2member_file_download_access_log = get_user_field(‘s2member_file_download_access_log’);

Is there an equivalent shortcode for this? Is there a count function for this?

Thanks