I just switched a relative's Speakout account from 25c/min to $30/400min/30d. If he uses all 400min before the 30d is up, can I pay for another monthly plan or is he stuck with 25c/min until the 30d are up?

Also, it says it will renew on Apr 1 but he may want to go back to BTM. Is there any way I can set it not to renew, without changing immediately to BTM? His balance is high enough to cover another $30 so I guess it won't change to BTM on Apr 1 due to insufficient balance.