Handling issues after Panhard mount replacement

Hi all, first time poster here. I've been enjoying BigJimny for a while leading up to getting my own, a 2016 Gen3. Unfortunately I've not had brilliant luck with mine so far, which brings me here.

I noticed a fair bit of corrosion on the underside but hoped for the best (you can probably see where this is going), and had a great time with it for a couple of months. Until, that is, the Panhard rod mount broke off the chassis while I was going around a corner, and it started handling like a shopping trolley. I got it home and the dealer had a fabricator attach a new one.

Since getting it back I've had problems with handling/stability. The steering seems to "pull" left and right on the road, particularly if the surface is even slightly uneven. It takes a fair bit of effort to keep it going where you want it to, and it feels quite dangerous above around 50mph. It can be fine, but there's the odd corner when it drifts in a direction unexpectedly and you need to be very on the ball to correct it, so I've found it best to just stay under 50. I know Jimny's don't have the best on-road handling to start with, but I'm certain I didn't have to watch the speedometer with this level of paranoia before.

I suppose I'm looking for some reassurance that this isn't normal. If they're going to need to start messing about with re-welding it, it will take a long time and I'm not confident I'll get back the car I started with. At this point I'm thinking whether to try to reject the car and get some of my money back.

Any advice or opinions appreciated.

It should be relatively easy to get the bracket in the right place especially in a workshop. It is much easier to not tighten the bolts to the correct spec. I had a really job on finding out one of my last jimnys panhard bolts wasn't tight enough. It's also possible that the bushing is tired either through age or because of being left in place while the bracket was finish welded, it wouldn't like the heat. So first off a spanner check that everything is tight and then a pry bar check that the bushes are firm. Those are easy and cheap after that back to the garage and get them to take it for a drive and explain that it wasn't doing it before their repairs and it's their problem.