I would cancel the contract if I were you.
The College Network is not a real college. Rather, it is a third-party publishing company that sells materials to help people prepare for exams. If you want to complete Excelsior's program, you can do so without spending tens of thousands of dollars on the College Network. Just enroll at Excelsior.edu directly. Bypass the middleman.
Many people have attempted before to get out of their contracts without success.
The College Network is funded, in reality, by a private loan that lacks the same protections (collection tactics, interest rates, wage garnishment, deferment, forbearance) that come with a government student loan. As I previously mentioned, the College Network is a publishing company, not a school of higher learning, so govt. student loan protections are not applicable when dealing with their loans.
If you were to stop enrolling in courses at a real college, you simply stop paying tuition. Since the College Network isn't a legitimate college, however, you do not pay for courses as you go, like you would at a real school, so you've gotta keep paying them even if you have not taken one single class or passed one single test with them.
Their payment structure is similar to purchasing a set of living room furniture over time with monthly payments. You sign the contract with an agreement to buy all the modules, so you're agreeing to pay for all the modules whether you use them or not. If you change your mind and no longer want to use the modules, too bad (you still must pay). Likewise, if you financed a bunch of living room furniture with an agreement to repay and later changed your mind or developed buyer's remorse, you still must make monthly payments on the furniture since you're bound by a contract.