The apology follows claims she made suggesting the Government had offered to cover outstanding payments.
However, Culture Minister Olivia Grange and festival organisers have denied those claims, insisting the event was privately funded.
Cardi B maintains she never received her full 2.5-million-US-dollar performance fee and says she will not refund the deposit already paid.
Meanwhile, organisers insist they fulfilled their financial obligations and are threatening legal action.
The event has been rescheduled for December 20.