Compliance is based on Love, Fear and Despair, you can see those by giving the slave the hypnovisor, Levels makes them increase their SKILLS faster (Slut, Pet, Sub), if you want a compliant slave you have to maximize one of those 3 stats, Love makes them fall in love with you, Fear makes them submit to you and Despair breaks them, you can use the talk options and rewar/punishment to increase and decrease those.