2007 Leon thinking it’s still locked

[Zoyaem]

Bought an 07 Leon, came with spare key only, got it home and discovered the key didn’t lock it at all, found a key in the door pocket which locked it but then deadlocked it, got a locksmith out and couldn’t get in so had to break a window, alarm went off so had to take alarm fuse out, was told it was the ignition barrel so got one and still hazards went off, then got told that it was the lock cylinder so went and got one of them and still the same thing, hazards wouldn’t go off but alarm siren went off too, then got told it was door mechanism, still the same problem, car starts and drives no bother but won’t unlock, central locking system not working now either, car is in safe mode so can’t plug computer onto it, basically the car locks but won’t unlock so she thinks she is still being broken into, we are on the verge of cracking up as it’s a brilliant car! Any help would be great!!