Hollaback = Hole in the back. Back with a vengence - double pun intended.
Hole is literary an open wound -that she has been backstabbed by those gossip queens in her pack, leaving a hole in her back. And to get back at those bad mouths, she 'tekan' them by making them do the routine again and again as in lyrics: "going round the track again"
Basically, a backstabbed victim coming back with a vengence!
Enough of those damaging words behind her back. You are making her a Hollaback girl. No Doubt she will get back on you!