When you applied for debt review the credit providers had to issue us with a certificate of balance confirming the total outstanding balance. Balloon payments and everything included. Thus, your balloon payment has been absorbed into your debt review and the monthly payment that you are making caters for the balloon payment as well. Your balloon payment has basically fallen away. Unless you cancel the debt review prematurely upon which all debt will revert back to the original contractual terms.
Regarding the cell phone contracts. They cannot simply give the contract to you without you accepting it. If they have done so they will be guilty of reckless credit. Are those accounts now included in your debt review? If they are not I would suggest that you speak with your debt counsellor to include them and investigate a case of reckless credit. It is against the law to grant more credit to a consumer who are under debt review. It is also against the law for a consumer to accept further credit whilst under debt review.
In all likeliness those two accounts will be dealt with outside the scope of your debt review, and you might have to call in the expertise of an attorney. If according to your knowledge you have not accepted those agreements, I suggest that you ask the cellular companies to send you the agreement which you have signed or the voice recording where you accepted the agreements. If they cannot produce proof that you have agreed to the new contracts, there is no need for you to pay them,