I just had a terrible experience with Air India at Terminal 2

I just had a terrible experience with Air India at Terminal 2. I arrived 35 minutes before the check-in deadline and i was waiting for 30 minutes, but when I tried to check in, their system wasn’t connecting. I was directed to another machine, which also didn’t work. Finally, a staff member at the manual check-in counter told me I was out of time because the system was blocked. I do know they have this rule but I was moving between different lines and I forgot about it. I assumed it's system fault so they would help in this matter. Instead, they claimed they had announced a call for Visakhapatnam (Vizag), but we( some 3 other people were also in line) only heard an announcement for Ranchi. Since it was an oral announcement, there’s no way to prove what was said. I argued for 5 minutes, but a supervisor eventually said they would help us outside the automatic gate. Instead, they escorted us out with police documentation for exit. This has been my worst travel experience so far, with absolutely no support from Air India at any step. Truly disappointing. What would you do in this situation?