Try Ban Mee Rak Nursery in Kathu, next to the Phuket Villa housing project - They charge approximately THB 5000/month, including breakfast, lunch & snacks. They teach English (2 days), Thai (2 days) and Chinese (1 day). They accept kids from 2yr to 5 years. All the teachers are thai, so don't expect international standards, but for kids in this age group, it is decent.