Upset girlfriend. How to make it up to her?

OK. I am a Malaysian who went on a visit to India. I told my girlfriend that I'll be back on the 31st of January but I had to extend my stay here till the 8th of February. My girlfriend got extremely upset and said quite some hurtful things.Well, very hurtful things but she is like that. She ignored her best friend's trip to some place as she made plans with me on the 2nd of February. But she's really upset now. How do I make it up to her now when I get back?