Sorry to hear you're having troubles.
I just wanted to offer my experiences to give you some comfort that ARC-8 wheels can handle stress in general. I bought a staggered set (9.5, 10.5) earlier this year strictly for track use. They were Road Force balanced with 265/285 Hankook R-S3's. I have NOT been gentle with these wheels. I have driven over hundreds of berms at tracks at high speed like Buttonwillow, Auto Club Speedway, LVMS road course, and Willow Springs. I have a couple days on the skid pad too with them---hehe that was tough on the wheels for sure. I've also been off-track a half dozen times into the dirt/rocks---although not at high speeds. At Auto Club, they've been at 150mph on the oval. (I also drive them to and from the track. Tracks are 60-130 miles away from me.) The wheels have over a dozen days on the track. I've gone through a couple sets of tires on the rims. I run over -3 camber on the front wheels. And I also have AP Racing brakes on all four corners. (I switch between street and race pads before and after events.) Through all of this, my wheels are still trouble free. And I see many other guys at the track who have similar success with their ARC-8's. They're very common at the track. At the last event, I believe I counted 4 cars running Arc-8 wheels with no problems that I was aware of.
In the world of wheels, anything is possible. The stresses are so dynamic and unique out there. But Apex has a nice reputation at the track with track guys for being affordable but strong and durable. I spoke to Eddy on the phone a few times when considering his wheels. He's a very helpful technical guy, and he took the time to give me solid advice about certain things for the track.
Anyway, I hope you are able to find a decent resolution to your issues. I just wanted to offer a few comments from someone who is putting the rims through some tough conditions and having good experiences.