So, show me where it says that the ability to forgive was to be ended with the apostles, or at least show me why it is no longer needed.
As a second comment, your ‘past their dispensation’ makes no sense whatsoever and isn’t backed up by anything. In other words, it’s an attempt to start with an answer, then find a way to prove it.
All I can tell you is to continue trusting that a man has the power to forgive sins and we’ll see how that works out for you in a 1,000 years from now. In the meantime, you are free to believe what you want.