It is possible that you are still finding lice after treatment because your treatment was not effective, the lice are resistant to the treatments you used, or you simply have not found or treated all the lice and their eggs yet.
To make sure you have eradicated the lice completely, you should use an effective treatment and be thorough in making sure you remove all the lice and their eggs. You should also clean your linens, clothing, and other items that may harbor lice.
It is also important to check your hair and the hair of other family members for lice since they can spread easily. If your treatment was not effective it is best to consult a physician for a prescription medication such as malathion or spinosad.