I have arranged my Round trip ticket with RJ to USA stopping over at Chicago and back to UAE. When I reached Chicago on the way back the ground staff in ORD wouldn't allow me on the flight blaming it on the PCR test and they asked questions about the email that I have received when, how? I provide them the details. However, I learnt after that they are buying time till the boarding is over and then they will say we are sorry. The Lady on the counter (R.M) and her manager walked to the room behind the counter acting that they were trying to solve my problem, but it seemed like it’s a well-rehearsed drama. during that time, I called RJ call center in which the gentleman on the other side of the call told me that it’s a full flight and they will not be able to provide me an alternative flight until 27th of Dec (Boxing day). Soon after the manager and her employee (R.M) walked out from the back room trying to apologies for the situation. I asked since its their mistake if they could offer a hotel at least and arrange a flight for the following day. They rejected and claimed that I did not show them the email of the PCR (in which I did) and it was my fault (treated as a no show), and they are not able to provide me a flight for the following day. They practically board their own first regardless of the situation and then other passengers. It’s a disgraceful airline No Ethics, No respect, No professionalism.