Complex sentence: Though rarely meaning to be rude, he often manages to offend those not used to his manner, and people overwhlemed by his personality and persuaded to give him credit regularly become less civil when they find their bills unpaid.
Split into simpler sentences: Though rarely meaning to be rude, he often manages to offend those not used to his manner. People are overwhelmed by his personality and are persuaded to give him credit regularly, but become less civil when they find their bills unpaid.