Hi,if you have backed them up before,recover from the backup files is the most efficient way.If not,MobiKin Doctor for Android could be a great choice,it's professional data recovery that can conduct a deeplu scanning on your device and then recover the lost contacts and media files on computer.

Nice sharing. Besides ways offered in the post, I share you this Coolmuster Lab.Fone for Android, which allows us to restore contacts and media files from all kinds of Android phone, such as Samsung Galaxy J7 Pro. It helps us access contacts and media files and recover them to computer via usb cable easily.

I will recommend the FonePaw Android Data Recovery which is a data recovery as well as the Wondershare. You can recover deleted files like contacts, songs, photos, videos, text messages, WhatsApp messages etc from your Android device. The program can support most of Android phones on the market.
You can see more details on their website.

The contacts lost from Samsung ,if you are going to retrieve deleted contacts on Samsung , you need a professional recovery software to help you. but if you have archived the contacts, you will have no problem getting them back because they have merely been hidden in another part of your system's memory.

NOTE: For instructions on how to back up app data, media files and contacts on the Samsung device, visit this thread.

Restore Contacts from an SD Card Backup:

1. Open “Contacts”
2. Tap “Menu” > “Settings”
3. If necessary, tap “Contacts to display” > “All contacts”
4. Tap “Import / Export contacts” > “Import from SD Card”
5. If necessary, select the desired backup file
6. Tap “OK” to confirm

Restore Media Files from the SD Storage:

1. Open the “Samsung” folder
2. Launch “My Files”
3. Select “SD Card”
4. Tap “Menu” > “Edit”
5. Tick the check boxes associated with the media files you want to restore
6. Tap “Menu” > “Move”
7. Tap “Internal storage” > “Move here”. Alternatively, you can restore the files to a different location by tapping “Create folder” or the folder name and tap “Move here”

Restore Media Files from a Windows PC:

1. Connect the Samsung phone to your PC via USB
2. Enable “File Transfer” / “Media device” when prompted or from the “Notification” area
3. Open the File Explorer on the computer
4. Locate the media file backups on the PC storage
5. Transfer the files back on the phone storage, preferably in the “Media” folder or the directory from where they originate
6. After the transfer is complete, eject the phone storage via system tray and safely disconnect the device from the USB port

Restore Media Files from a Mac Computer:

1. Connect the Samsung phone to your computer via USB
2. Enable “Media device” / “File Transfer” when prompted or from the “Notification” area
3. Launch Kies on the Mac and click the “Back up / restore” tab
4. Go to the “Restore” tab
5. Tick the check boxes associated with “Music”, “Photos” and other file types you want to restore
6. Click “Restore” and follow the on-screen prompts to complete the process
7. Once the transfer is complete, drag the phone’s virtual drive from the desktop and drop it into the “Trash can” to eject it
8. Safely disconnect the device from the USB port