Without pictures, it's hard to say, but if I'm understanding your descriptions correctly, your pool probably can be repaired, BUT . . .
1. If the liner split vertically, or if the split is more than 1' long, repairing it is a pretty doubtful job. A vertical split will be stressed, when you refill the pool, and the new patch will not have the same elasticity or strength as the original. I think you probably ought to give up the idea of repairing the liner as a bad job, and just replace it.
2. It's possible to patch over a split section of wall, but you'll need full access to the inside of the wall. You also will need non-corroding patch . . . which pretty much means you'll need to patch with stainless steel sheet metal, and then attach it with pop rivets (see pic below). You should be able to find a restaurant supply contractor (they make the stainless steel bars, sinks, hoods and shelves in restaurants) who can supply you with what you need. Some HVAC duct fab shops also work with stainless. Regardless, you won't be able to buy the patch off the shelf. Here's a picture, grabbed from Google, of pop-riveted metal:
Be SURE to use SS, or at least all aluminum, rivets. Otherwise, the rivet will rust. Use high-grade duct tape (like Gorilla Tape) over the edges, seams, and rivets to protect the liner.
3. I suspect you'll have a hard time getting anyone in the pool industry to do this for you. I think you may be better off doing it yourself, if you have the skills, or hiring someone who is a tradesman. A moderately skilled HVAC guy should be able to do this with no problem, IF you explain to him exactly what needs to be done.
Good luck!
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