Downloading Prepaid Photoshop onto new laptop

Hey,

I paid for a years use of Photoshop in 2015 which then automatically renewed in 2016. I cancelled the automatic renewal and received confirmation that I still had access to Photoshop until 30th September 2017. I bought it and downloaded it on my old Laptop (Acer, Windows) but I now have a new laptop (Mac) and wish to install Photoshop onto it, however I cannot find a way to download it onto my new laptop without buying it or purchasing the free trial. Any help would be very helpful!!  Thanks!!