Round limits in the gauntlet

Many more times than not, when I get to level AA and/or AAA in the Gauntlet, I always seem to never get past - because I end up in too many battles where the opposing characters have a combination of immunity, revives, and healing which can't ever be beaten. Many times, I'll kill each of the individual characters many times, but then have them all revive with immunity and healing. Is there any way to declare victory in the Gauntlet if you're both still going strong at 20 or 25 rounds? I'm just about maxed on relics, have been playing non-stop for over a year and I still can't get past level AAA because I keep getting caught in 'perpetual' battles, where I eventually need to quit after 30-45 minutes (and not able able to use those characters again). No battle in the gauntlet should take over 5 minutes - 10 tops. How do we fix this?

Thanks!