This is old K-pop lore so pardon me if I get things wrong because it's been a long time ago, but I'll try to remember and dig out as much as I can.
B.A.P went on a 'tour' in 2016 and one of their stops was in Itay. Did they perform in Rome, you ask? Milano? A big city? No. Even though the tour poster said they would be performing in Milano, their actual concert location was in a small city next to it.
If you look up PalaYamamay, you'll see it's actually in the city of Busto Arsizio, a smaller city compared to Milano, which is situated in the province of Varese, 35km north of Milano. While Milano homes over 8 million people, Busto Arsizio has the population of around 83 thousand, for context. Their location was this.
So we're off to a bad start to begin with. The concert is advertised to be in Milano, but is taking place in a sports hall. What could go wrong?
You might wonder why this was the case. Why they were sent to a smaller city, to a city's sports hall, why they were performing there to begin with.
It all comes down to the organizers - Kpop Agency. Literally, that's what they are/were called. Kpop Agency. The people who brought B.A.P to Italy were called Kpop Agency. And their chairman? His daughter was a K-pop fan, Zelo biased, so they decided to bring the group to them, to their city.
It's no wonder that on their official page, the first three (and for a long time the only) photos they decided to post were of her.
The photos are still there, as is their site which hasn't been active since 2017. Just look up 'Kpop Agency Italy' on Facebook and you can find them.
This is not the worst part, not even close. I don't know how much TS Ent was paid. I don't even care. Whatever they were paid - it wasn't worth it. Because what comes next is one of the most degrading things I've ever heard an agency make an idol do publicly, and I think it was pretty pathetic of them to make him do so.
The day after the concert, the rest of the members were left unattended so they explored Italy and Milano by themselves, but not Zelo. He was forced to accompany the organizer's family, especially his daughters, on a shopping trip. He was there to entertain the older daughter, his 'fan'. He wasn't allowed to talk to other people who were pushed away from him and told to leave him alone while he apologized (this all comes from fan accounts) and he carried the girl's shopping bags for her the whole time.
For example, Yongguk and Youngjae were having fun with each other that whole day and spent time sightseeing, shopping, exploring and freely interacting with fans, while Zelo wasn't allowed to do any of that. The fans who approached Zelo to ask for an autograph said they were pushed away by the daughter and poor Zelo was stuck with a language barrier, not knowing what was going on but still apologizing for something he wasn't to blame for to begin with.
When I tell you I was pissed! I remember how angry the Italian fans were at the whole situation. What I didn't mention is that the "concert" hall didn't have medics on site, nor shops nearby so people couldn't even buy water, they didn't have an organized queue and they let friends of the organizers in with special passes while everyone else waited for hours outside, a lot of the people who paid for VIP tickets didn't get the VIP treatment and none of the presents promised because they ran out of them (because they gave them out to the friends and family of organizers) and so on.
The worst thing is that another agency which was experienced in organizing concerts was supposed to be holding their concert in Italy as well and that's why the posters said Milano - it was supposed to be there and not nearby, but at the last moment this agency offered more money and TS Ent only cared about that. 
I dug up whatever I could find, I wish I could find more fan experiences from that day but unfortunately the new engine searches are shit so nothing comes up (but I did find this OH thread which confirmed a lot of the mess I remembered from that time https://onehallyu.com/topic/327042-mess-bap-italian-concert/).
