Complex sentence: He's always promoting the store and its products in street graffiti and even in ordinary conversations, but the quality of the products sold is often questionable, as many people have complained to him and/or his father often.
Split into simpler sentences: He's always promoting the store and its products in street graffiti and even in ordinary conversations. The quality of the products sold is often questionable, as many people have complained to him and/or his father often.