If it’s saved to the phone memory card just remove the card and put the card in a card reader on your computer to access them. Alternatively download the Samsung phone management software from their website for your particular phone to your computer and use that with your phone connected with its charge USB cord to the computer.

Is your phone an Android phone? If your Samsung phone is Galaxy, you can use Samsung target="_blank">Samsung Data Recovery

Several steps for you to take your phone card messages and images back:
1). Keep this phone memory card away from anything new and insert it to your computer with this phone or card Reader.
2). Download and install phone memory card target="_blank">http://www.tomshardware.com/answers/id-1649375/restore-data-micro-card.html

Hello! How's your situation? If you do have rescued your phone target="_blank">http://www.4cardrecovery.com/howto/memory-card-photo-video-recovery.html
Hope this works for you.

OK! If you are sure you've saved them all on the phone memory card in advance, you can try some phone memory card target="_blank">http://blog4mark.blogspot.com/2012/12/samsung-phone-recovery.html
Stop using this phone memory card and insert it to computer. And then, download this data recovery software and check whether it can find and restore your lost messages, images and more.
Note: From now on, make phone card data backups all the time to avoid similar data loss problems.

I don't think it's technically possible to get the lost messages back from a SD card. But as to photos, you may connect it to your computer via a card reader, then run a photo recovery program to get them back. Here's also a tool for you if you happen to be a Mac user.
Recover Digital Photo Music and Video on Mac OS

Get yourself a SD card adapter and save them to your computer and then to where ever you want.