See pages 11 through 17 of this publication: http://www.texasbar.com/Content/NavigationMenu/ForThePublic/FreeLegalInformation/ConsumerTenantRights/Tenants'RightsHandbook.pdf
This will give you a thorough and DETAILED description of your rights and remedies and the procedures you need to follow. At this point, if you have not originally given notice of the problem in writing by certified mail, it sounds llike you need to go to the step where you would provide the second notice by certified mail. 10 days is more than a reasonable time for the landlord to have fixed the problem, so start with the step discussing the second notice in writing. Good luck.
I am not your lawyer and an answer on AVVO is not intended as legal advice but is provided for general informational purposes only. If you desire legal advice, please consult a lawyer and form an attorney client relationship.