Complex sentence: The ads contained small cartoon characters (the "Q-ies" or "Q-δάκια" in Greek) that resembled the company's logo, and used slang to promote the company's offers and slogans, such as "no fixed fees".
Split into simpler sentences: The ads contained small cartoon characters (the "Q-ies" or "Q-δάκια" in Greek) that resembled the company's logo. They used slang to promote the company's offers and slogans, such as "no fixed fees".