Loose/ Rocking Driver's Seat

I am having a problem in which my front seat is loose causing me to rock back and forth in the driver's seat from the momentum of starting and stopping. I've had the dealer fix it twice and deny the problem a third time- stating the "play" in the seat is from the factory. My faulty memory seems to recall the dealer replacing a bracket the first time it was fixed but I can't find the paper work to verify this. The axis of the rocking seems to come from the driver-side front of the seat and the passenger-side rear of the seat. Has anyone encountered this and found a possible easy fix? I suspect that taking it back to the dealer will yield disappointing results.

There are only four bolts holding the seat down. The rear two are covered by small plastic caps. I think the front two are expeosed. If they have tightened these bolts before and they've re-loosened, then maybe the threads on one of the bolts or the holes (start praying for stripped bolts now) are stripped.

I suggest this because I had an exhaust leak problem years ago that was fixed over and over and over again until the tech got sick of fixing it and finally looked at the bolts. Yes - they were stripped, and the problem finally got fixed properly by replacing the other side of the connection.