Help with phone problems

In this post I reprint some phone enquiries that have been submitted to the help desk in August.

I have a Smartphone LG G4 International (H-815) Android version 6.0.
On 29 July I was deleting stuff using the Smart Cleaning software incorporated in my device with the intention of freeing space in the internal storage. I deleted by mistake (ignorance?) cache files and DCIM files (which I understand are the support of photos and videos) so a good bunch of pictures and videos went missing after my stupid action! When I tried to find them in Gallery they were not there any more.
It is also posible that some files were also deleted 10 days before then when I unloaded the content of the phone (again pics and videos) on my laptop having chosen the option ‘delete after transferring. But because the ‘C’ drive of my laptop was nearly full, some files could not get transferred – I wonder if some were lost also in this proccess.
HTC 10Happened what it may have happened on these two occasions, I wonder if you could help me to retrieve my lost files. I am only after videos and pictures really.
Additionally I want my contacts back. These are perhaps the most important as many of my business mortgage contacts are on the phone.
Your help would be appreciated.
I live near York, close to Leeds in Yorkshire. Some time soon is quite convenient for me. I can leave my phone with you next week.
NOTE: I have tried to avoid taking more pictures and videos since then to prevent over-writting empty picture/video files. [Ed note: Contact ICT LEEDS for advice with this one]

My phone is a HTC 10 which has had rain ingress Sat 12th Aug. It at first set everything going all at once. Flash light came on, and various other items like bluetooth,gps,etc all switched on and the phone had the booting up spinning logo showing in the background of the screen as a ghost image. The phone then switched off or died. I sttod it up in a warm place for the rest of Sat/Sun. This morning Calling my phone provider EE they suggested trying the power on and volume button down to reboot (I thought it should be volume up ?) Nothing happened. Can you retrieve my contacts and data. ?. And what data protection do you provide.

I have accidentally deleted the photos from my camera folder on my Samsung galaxy s3 and just wondered if you get get them back for me.