ERROR WHEN USING COUPONS/VOUCHERS/REWARD POINTS

I am trying to get a coupon to work - initially when the customer enters the coupon it will say that it has been expired or overused - i changed the amount of times to be used to 999 and per customer 999 - i tried the coupon again same error - i signed out of the account then back in - the coupon was applied at that time - then when i attempted to checkout by having a coupon it removed all payment options and said to contact admin.
SAME ISSUE HAPPENS WITH VOUCHERS AND REWARD POINTS

I am using 1.5.4