Is it permissible to deceive one's father to obtain additional money beyond what is needed, under the pretext of a scientific course?

A father is not obligated to financially support an adult, wealthy son. There is a difference of opinion regarding his financial support for a poor son; the majority of scholars, with the exception of the Hanbalis, hold that it is not obligatory after puberty. Study expenses are not considered part of the obligatory financial support. Therefore, your father is not obliged to pay for your course fees, and whatever he pays is a donation. What you are doing by inflating the amount and deceiving is unlawful (haram), and you must repent and return the money to him or seek his forgiveness. It is permissible for you to request wages from your father for your work in his shops, but it is not permissible to take it without his knowledge.