cabbage likes cold weather to produce nice heads, I am guessing it is very warm now where you are and that is the reason for them bolting. If you have seed left over from the first planting I would replant now for a fall crop that should be harvest able in early November. If not then cover the cabbage with a row cover for winter and just keep it from freezing and it will be perfect by may of next year.
I just put in some spinach seed for fall harvest and will be putting in collards with in the next week. all those like cool weather to grow in nothing above 65-70degs during the day with cooler nights.