What do I do? Relationship problem?

Okay so supposively I'm going to visit my girlfriend on January 2nd which is tomorrow and I've booked my flight already but her parents don't like me and I've never done anything wrong to them or their daughter, I'm 18 and she's 17 my mom wants to phone them to speak to them about me going there but her parents is making everything hard for both of us we love each other so much, I cried so much last night and she did too, she selfs harms too so it makes me sad, I was on the phone with her last night trying to get her mom to talk but both of her parents just yells at her and then smacks her, I can't do anything because she just recently turned 17 id have to wait another year, should my mom call because I have their phone number I really wanna see my gf my heart is aching and I have so many stuff for her that I bought, I just want a chance to make her parents see I'm a good guy because they're thinking I'll be like her last boyfriend who was nothing but bad, my parents heard her parents swear over the phone too mentioning my name, I never did anything wrong to them I wanna meet them so bad, my flights tomorrow and I can't go if this isn't fix I only have about 15-18 hours left to fix this and do something about it please someone help I really really really love this girl I don't want to lose her :'(