The teacher just stopped taking the monthly fee for my son's piano lesson out of my bank account without any kind of explanation.
ーThe teacher just stopped taking the monthly fee for my son's piano lesson out of our bank account without any kind of explanation.
「先生が何の説明もなく、息子のピアノのレッスンの月謝を口座から引き落とすのをやめました」
to take the monthly fee out of one's bank account で「銀行口座から月謝を引き落とす」
without any kind of explanation で「何の説明もなく」
ご参考まで！
カナダ 
