If you relied on the representation that the shot would be changed to join or rejoin, you can claim fraud in the inducement. One can not fraudulently induce or trick you into entering into a contract and the insist on performance despite their material misrepresentations.
The operator may be a good guy, but he joined the league officials to represent that the shot would be changed. They had a duty to know. Stated differently, they knew or should have known that they could not do what they promised. They also knew or should have known the limit of their authority.
Either way, I would not be forced into staying or paying if they misrepresented things to get me to join.
By the way, I have bowled for only 4 years. However, I do not recall ever signing a contract to join the league. By paying the USBC fee and signing the card, that is likely the basis of the relationship. I have not read the card but I am guessing it says I agree to USBC rules.
That agreement would not be a defense to your claim that you were fraudulently induced to join that particular league. In fact, I would guess that there is a USBC rule prohibiting this type of misconduct.
Whether the USBC person addressing this particular issue for you (if it gets that far) will have walk and tie my shoe sense is a different question.