What to do when your mom says this?

I dont know how to say this... This is an incident I wanted to go meet my friend somewhere...I wanted to go to this place since so many months... I asked my mom for permission and she replied in a very hanging way...Its like go if you want to....I asked her to say in a definite matter and she said why will I ask you to spend money on dinner outside....Now this is where it hurts...I have never spent a single penny on me...All my money coming from my relatives is stored away for future...They have never spent much money on my education as I always got scholarships and stuff...I have not met my friend for months...I dont have any pocket money, never get any...Its not like they have a financial issue they just dont wanna spend on me...I dont even use 100 rupees a month...Don't know how to react...Should I defy and rebel?