Did the repair shop tell you what they did exactly to "clean" the water away? You should call them them and ask. Water damaged phones can have a wide range of problems, many times they are difficult or impossible to repair properly.
If you are comfortable opening up the phone, you can try :
- Open your phone and remove the logic board (follow this guide)
- Inspect the logic board, especially around the connectors and look for corrosion.
- Inspect both sides of the board. Unfortunately, 80% of the board is covered in shields. That's usually where the damage is occurring.
- Put your board in a container with >90% isopropyl alcohol and let it sit for a while.
- Use a soft brush, like a toothbrush and lightly brush away any corrosion you see.
- Rinse in alcohol and repeat.
- Let it air dry for a day.
- Re-assemble and hope for the best.
- You should also consider getting a new battery
A professional repair shop that does water damage repair may be able to recover your phone or the data because they have access to pro-level ultrasonic baths and specialized cleaners as well as the skills (and parts) to troubleshoot your board. Many shops have a no fix/no fee policy so you don't have to spend money to find out if the phone is fixable or not.