You imagine it like suing them will resolve the issue at hand. What you miss is the concept for barrier to entry. Even without an explicit policy to ban competition (which is imho a libertarian fiction), the capital and man-hours of investment necessary to enter a market could be enormous. Even more if you want to compete with established players there. E.g. you have hundreds of carriers around the world, thousands of banks, and god only knows how many hardware configurations needing support to a 99.995% coverage of user needs. Not even counting the language barrier for dealing with them, this is overhead that nobody can afford without good backup investment and a clear path to profitability.