My best friend pass away two years back and when his wife tried to get into the safe, no go. She needed some of his military papers and insurance papers he had stashed in the safe. Her brother and nephew jacked with it for an hour. No go.
She called me and when she told me they had been jacking with it for most of the day, I told her, it will probably not open without locksmith. I helped my Digital/Electronic challenged friend set up the safe, set the combo and store the combo in a safe place. I think he had jacked with it before he passed, maybe changing the combo with out knowing. He screwed up several I-Phones, one I-Pad and several electronic devices in his home when I told him to not touch them again and I would get them right for him and invite my 8 year old nephew over to fix them. He didn't like that but that's the truth.
I know a guy, "You've heard that before", that worked for Bear Safe Co in Oklahoma City and was now a lock smith. He has an electronic code searcher/ Re-coder piece of equipment for unlocking digital equipment. He took the face from the lock, hook up three wires, and turned it on. It sat there and ran numbers for about 10 minutes, erasing everything in the lock and installed a new combination in the lock and then opened the safe. Before it was closed again, I made not of the combo for myself, the wife, and put it two places in the house so she could find them but asked her not to try and open unless Myself or here Brother in Law was there. It cost $250 for the locksmith to drive 200 miles round trip, unlock and set new combo. I was ready to cut the back of the safe out with a grinder for her when I found him.
Good luck with yours.