GE MoneyBank

I made a double payment in March 2009, to avoid late charges. I should have been paid ahead by one month. I continued making double the amount due each month for April - August, and again made a double payment so I'd be two up going into winter. I then received a bill for September saying I owed another payment, plus I've been being charged $39 per month for late fees! I contacted the co and they tell me you can't pay ahead and since the payments were 2-4 days late (when I got paid), I owed the $39. They will only reverse one late charge per year.