Pathfinder – My general manager refuses the valid dialogue of my character because of his weak charisma. How can I change my GM's notice?

This is the first time I play D & D. As a result, I may have botched my character's stats. I have a weak statistic of charisma. However, in my understanding, this should only be a modifier of how I play my character.

However, what I recently heard my deputy minister said: "Yeah, this line was great and it would work, but you have a charisma too weak to use it." Several times.

I want to convince my general manager that it is not because I have a low CH statistic that I can only say, "Me, Grug, break me."

How can I do that?

EDIT: Since there are questions about what happened, the problem is this: there has been an unfortunate accident resulting in the death of an officer ("ruler") who has been killed. an "empire" kobold), of which we have been accused. However, the ruler died with the "help" of magic and we were mere adventurers (a warrior, a barbarian and a thug). After asking something, it became clear that, by pure coincidence, it seems that after the death of the ruler, the shaman of the Court takes over and that he was the ruler before the coronation of the deceased deceased. I do not remember what I said exactly, but I wanted to point out to the main general (who seemed reasonable, honorable person) that maybe, it's maybe a coincidence and that it's a good thing. they, with our help if they wish, can further investigate the matter.

I was told "yes, it's good reasoning, but you have 11 charisma, so you can not say that".