I saw this tabbed before, and this is based off someone else's. Some of the chords 
were off and I really like this song. Tabbed by ear, probably 99% right. Enjoy.

Intro/Verse
e|--------------x-------------x--| (022000@1)x3 	
B |------7-------x-------2-----x--|
G |------7-------x-------2-----x--|
D |--------------x-------------x--|
A |--------------x-------------x--|
E |------7-------x-------2-----x--| Fingerpicked
                 ^Slap         ^Slap
Then 1x
             Ee (022100@1)|-----0-------| 
B |-----0-------|
G |-----1-------|
D |-----2-------|
A |-----2-------|
E |-------------| Strummed

Repeated for all intro/verse.

The Bm is played barred. You can play the A barred or just a regular A for the chorus.

Chorus
E (022100@1)                     Bm (x24432@1)          AI'll (x02220@1)never leave You Heartless

EHeartless (022100@1)                                  Bm (x24432@1)          ANever (x02220@1)leave You standing in the darkness

EThe (022100@1)darkness
               Bm (x24432@1)         A (x02220@1)Darling oh I Promise

EI (022100@1)Promise
                     Bm (x24432@1)         AI'll (x02220@1)never leave You Heartless

EHeartless (022100@1)
2nd Verse
e|--------------x-------------x--| (022000@1)x3 	
B |------7-------x-------2-----x--|
G |------7-------x-------2-----x--|
D |--------------x-------------x--|
A |--------------x-------------x--|
E |------7-------x-------2-----x--| Fingerpicked
                 ^Slap         ^Slap
Then 1x
             Ee (022100@1)|-----0-------| 
B |-----0-------|
G |-----1-------|
D |-----2-------|
A |-----2-------|
E |-------------| Strummed

Another Chorus.

Bridge - The A2 and A3 chords are below. G and F are Barre.

A2*                                A3 (14xxxx@9)  G (320003@1)  
Oh no I'm never gonna ever let You down down down
A2*                                A3 (14xxxx@9)  G (320003@1)  FI'm (133211@1)never gonna ever gonna let You down down down 
A3 (14xxxx@9) G (320003@1)  F (133211@1)          
Down down down
 
Chorus x3

Fin.

A2*
e |-----x-------| 
B |-----0-------|
G |-----0-------|
D |-----5-------|
A |-----5-------|
E |-----5-------| 
  
             A3*
e |-----x-------| 
B |-----0-------|
G |-----5-------|
D |-----5-------|
A |-----5-------|
E |-----0-------|