At my Church the service is the Bible study. I don't mean for that to sound haughty, but most of the service is spent in Bible discussion. We do have music and praise and the offering, but the rest of the time is spent in the scripture. So no, there are no extra Bible study classes, although it's occasionally there have been extra services (or lectures) offered.

Gal 2:16 Knowing that a man is not justified by the works of the law, but by the faith of Jesus Christ, even we have believed in Jesus Christ, that we might be justified by the faith of Christ, and not by the works of the law: for by the works of the law shall no flesh be justified.

Jas 2:24
Ye see then how that by works a man is justified, and not by faith only.