Sorry to hear about your trouble with your Facebook Ad, they can be a huge headache to deal with. I've had numerous accounts banned in the past because they are very strict with what advertisements they allow. In the past, when I've had an ad removed, they normally sent a message explaining why. In addition, they've linked their advertising terms and conditions.
Your product looks like it would have no problem being posted, and I wonder if it maybe had to do with your copy or something else. Did you have a chance to read through their advertising terms of service? That might provide some insight into what happened.
Otherwise, I'd personally make a new ad and just keep trying. When they've banned me in the past, I've simply made another Facebook account to use for Business Manager. Not something I'd suggest for everyone, but it has been working for me so far! Hope that helps or can add some insight.