It sounds like we both have similar issues. To be clear, there is only one magnet, which is on the flame.
In my case, the black metal circular piece of the batmobile that the magnet of the flame attaches to came off. It’s basically a large painted washer that’s held on to the batmobile with two sided tape and the adhesive gave out. Also, in my case, the paint on the washer peeled off for some reason where the magnet of the flame made contact. It looks like the stainless steel of the washer wasn’t correctly prepped for paint as it flakes off to the touch.
Can you tell me when you reported your issue and what parts did you receive?