I had to withdraw from DMM Eikaiwa due to insufficient funds
「銀行の残高不足でDMM英会話を退会させてしまいました。」は英語で「I had to withdraw from DMM Eikaiwa due to insufficient funds.」という表現が良いと思います。
残高ー(Bank)Balance
不足ーInsufficient
退会ーWithdraw
例文
「このサイトから退会しようと思う。」ーI think I will unsubscribe(Withdraw) from this site.
「彼はそれを退会するでしょう。」ーHe will probably withdraw from that.