What is the ruling on unlocking encrypted phones for use on other networks, and what is the ruling on a sales contract that includes a condition prohibiting their use on other networks?

The company combined selling phones and leasing service in one contract. This is a point of contention among scholars, but the preponderant opinion is that it is permissible. If combining sale and lease in one contract is permissible, then the contract becomes binding, because "Muslims are bound by their stipulations," and this condition does not fall under the religiously forbidden monopolization.