Subscriber agreement regarding cancellation

I have a leased 622. It replaced a 5?? last April The paper work left by the installer contained nothing about the financial & cancellation conditions. The manual does contain a agreement that says some promotions may include a minimum term but nothing specific. A cancellation fee of around $300 is mentioned if cancelled before the term. So could I cancel (if MLB is gone)? Shouldn't I have a signed agreement?

Hope not to cancel.

Shorty