Medibank policyholders should check there are no problems with their automatic payment set-ups, with many complaining about incorrect or irregular direct debits. The latest quarterly bulletin from the Private Health Insurance Ombudsman shows the biggest cause of complaints in the three months to December was problems with premium payments, and Fairfax Media can reveal it largely related to one insurer: Medibank. "[Premium payment problems] predominantly concerned direct debits from bank accounts and credit cards, such as incorrect debit amounts or irregular debits, or the accidental cessation of direct debit arrangements," the ombudsman said. Medibank, out of 36 health funds, accounted for 48.4 per cent of all complaints, and 22.2 per cent of all disputes, despite having a market share of 27.6 per cent. However, Medibank's share of complaints has dropped from 60.7 per cent in the previous quarter.