It's been over 6 months since my facial contouring surgery, but I can't open my mouth and it even makes clicking sounds… This isn't normal, right?

I am writing this because I feel so frustrated... It has been over six months since my family member had facial contouring surgery, but I am extremely worried because their condition is still very strange. At first, the hospital told us that it would naturally improve over time, so we trusted them and kept waiting. However, even now, their mouth still doesn't open wide, and they continue to experience discomfort during daily activities. There is also a clicking sound coming from their jaw every time they chew. At this point, I suspect there might be something wrong rather than just slow recovery, so I recently visited a university hospital for a separate consultation. They told me that their current condition does not appear to be a normal recovery process. However, the original hospital where the surgery was performed keeps repeating that it will get better with time, so honestly, I feel very confused and frustrated. I am wondering if anyone has had a similar experience, and I would appreciate your advice on whether it is right to just keep waiting in this situation or if we need to consider a different course of action. Also, if this situation escalates into a legal dispute, I am wondering if we should consider a medical malpractice lawsuit, and if so, if we proceed, whether it is appropriate to look for a lawyer specializing in this area.