Can i fix my credit report?

I have some old credit write offs on my credit report from when i was younger and didn't know what i was doing. now i'm older and in a place to actually start paying off these debts. but i have read that the credit write offs mean that it will stay on my report for seven years no matter if i pay or not. Can i call up the collection companies and tell them i won't pay unless the take it off my report?