Get yourself a USB Card reader for your computer. Then boot the computer using Hirens boot cd to do data recovery off the sd card.
I have done this a couple of times before personally.
I suggest doing this as hirens boot cd software lets you go multiple levels deep in doing deep scans for data recovery giving you the best options to getting the files back fully. Sometimes doing data recovery on memory cards don't work out so well, as you will half corrupt the image file.
What software did you use to do data recovery? Do you have the option to do a full scan on the memory card, it will take hours to complete.