I would NEVER take that MacBook to whoever did your "Service" again. They didn't even attempt to backup your data?
First off, STOP USING the MacBook IMMEDIATELY. That means, if you're using it now, SHUT IT DOWN and use another computer.
Further use may result in old data is being over-written.
You could TRY using something like DataRescue on the internal drive.
But you're going to need ANOTHER Mac, and try to run the problem Mac in "target disk mode", if possible.
Then you can "aim" the data recovery software at it, and let it "do its thing".
SOME of the photos may be "recoverable", some may not.
Here's how a data recovery app works:
1. You download the app for free
2. You launch it and "aim it" at the problem drive
3. The software "scans" the entire drive, and will give you a report of what it finds that it believes to be "recoverable".
4. The software will let you recover ONE FILE ONLY as proof that it will work.
5. If things look good, you now pay the registration fee, get a code, enter the code, and the software goes to work on the drive.
6. Be aware that you'll probably lose all previous folder hierarchies and file names. This is "par for the course" with data recovery.
Again, things aren't going to go well if you run this from the "damaged" Mac. You need to boot and run it from another Mac.
You also need to learn something about the concept of "backup".
I realize it's a tough lesson to learn. Most of us have been there before (and that includes me).
I would suggest:
1. CarbonCopyCloner - the best backup utility of them all
2. An extra hard drive to serve as your bootable cloned backup.