Balances accruing interest on credit and charge cards have hit their lowest level in seven years, as consumers continue to pay down their personal debt.According to the latest Reserve Bank credit and charge card statistics, balances accruing interest fell from A$33.1 billion in June to $32.2 billion in July - the lowest level since December 2008. The average balance accruing interest per account in July was $2000. The average has fallen by around seven per cent over the past 12 months.Consumers made 188.7 million purchases on their credit and charge cards in July, worth $24.7 billion.The value of purchases was down three per cent on the previous month but up five per cent on the same time last year.MWE Consulting said consumers spent an average of $18,690 per card account over the 12 months to July.Lending finance statistics released by the Australian Bureau of Statistics on Friday showed that new personal finance commitments fell 2.6 per cent in July, compared with the previous month.The number of accounts rose 0.2 per cent to 16.1 million in July, compared with the previous month, and 3.8 per cent compared with the same time last year.