I have just set up automatic top-ups on my Petrocan account. I can set the renewal timing to every 120 days and at an amount of $25 for 120 days. Anyone know if Petrocan will renew before the old time expires, so as to preserve a remaining balance, or do they allow the old balance to lapse and then put the automated top-up in, starting from 0?

I have a reasonable balance on the go now and am not 100% sure I want to just let it go and see.