Yes, you can get access to free French or Dutch classes in Brussels. Sometimes you must pay, but it costs very little. An institution called VIA offers free A1 and A2 level French language classes as an exchange for following the integration classes with the (integration classes also free). There is also a sister institution called Bon which offers the same services but in Flanders. In any case the refugee can always ask their social assistant to reimburse them the money they pay as a tuition for language classes. Most of the time, the social assistants are nice enough to reimburse the full amount. Please go to your commune to check if French or Dutch lessons are available.
Babbelkot also offers French lessons in Brussels free of charge where parents can bring their children with them: http://www.welcome-babbelkot.be/activit%C3%A9s
Erasmus+ also provides free online courses for refugees. For more information: http://ec.europa.eu/programmes/erasmus-plu
You can also hire a private tutor to improve your mother language skills. See…
http://www.findmyfavouriteteacher.com/students-home.php?lang_id=en