Credit question about an almost 7 year old debt.?

Is an almost 7 year old college housing debt (I broke a lease agreement, did not stay in the housing dorm) considered a written contract under the statute of limitations, or is it characterized as something else? Somehow a collection agency got a hold of my cell phone number and now they are trying to collect on this delinquent account that is scheduled to be removed from my credit report this coming September. (I haven't called the collection agency, I've only listened to the messages, I don't want to make the mistake and verify this debt and start the 7 year reporting period again) I just want to know the right SOL defense to ward this collection agency off and follow it up with a cease and desist letter.