New SIM activation in Cuba

good afternoom, i bought an iphone xsmax and i have been using it with ooredoo SIM in Qatar but right now i am on hollidays in Cuba and when ever i try to activate a local sim the phone says that i must request from your company to unlock my phone. i have not been able to use my iphone because of it, I call my phone company and they claim the phone is not blocked by them, I received the same answer more than once, they say my iPhone should be working world wide, can you help me please