its relatively a longer period ie 3 months with your infection .Augmentin is one of the preferred antibiotic for ear infection .You have not mentioned what type of infection ?minimum 5-7 days days antibiotic use is in practice
Next Steps
Dont negelect long standing ear infection.Consult ENT specialist to examine your ear and come to definite conclusion to manage it further
Health Tips
prolonged ear infection can lead to many complications .Don't buy OTC medicines