This is my first tab, so don't be too rude!

This is the mashup that Bieber did. I couldn't find the chords anywhere, so, here it is :D
-Hannah-who-loves-Bieber-and-Darren-Criss


Am                                         Dm   Am                                              Dm
How could you be so heartless? Oh How could you be so heartless?
Am
You were my sun 
E
You were my earth
C                                                    G
But you didn't know all the ways I loved you, no
Am
So you took a chance
E
And made other plans
C                                                                  G
I bet you didn't think that they would come crashing down, no

You know why?
Am
Cause in the night, I hear them talk
                    Dm
The coldest story ever told
                     F
Somewhere far along this road he lost his soul
                                       Am Dm
To a woman so heartless
                                                   Am Dm
How could you be so heartless?

That's why I said,
Am
Hopped up out the bed
              F
Turn my swag on
                                          G
Take a look in mirror said "whats up?"
                          C
Eh,  I'm gettin money, Ohh, Ohhh
              Am
I want the money, money and the cars
                       Em
Cars and the clothes, the shows, I suppose
                           Am
I just wanna be, I just wanna be successful
                          Em
I just wanna be, I just wanna be successful, yeah, said
Am                     Em7
I just wanna be, I just wanna be successful
       Am
And, In the night, I hear them talk
        Dm
The coldest story ever told
                     F
Somewhere far along this road he lost his 
                                   Am Dm
 A woman so heartless
                                                  Am Dm
How could you be so heartless?