My 4 year son has an ear infection. They purged the ears but he doesn't seam to get better. What should I do? Thank you

Antibiotics. I am not sure what you mean by purging ears - cleaning? Tubes? If he has not been treated with antibiotics, it may time to do so. If he had one antibiotic that proved ineffective, then he may need another. There are resistant infections that require a more potent antibiotic than just regular first line choice such as amoxicillin. If antibiotic is ineffective, other causes should be explored (funga.
See his pediatrician. I agree with all of the other answers. I wanted to add that children are more prone to ear infections because of the angle and size of their eustachian tubes. This tube goes from the middle ear (behind the eardrum) to the back of your throat and equalizes the pressure and drains the ear. In children it is shorter, more horizontal and narrower leading to blockage and infection more frequently.
Have him rechecked. From what you describe, it sounds like they washed the ear wax out of his ears to either get a better look at the ear drum or to see if it would help with the pain. If the pain has continued, he needs to be rechecked by a doctor to make sure there is nothing more serious going on with his ears.
Return to doctor. Ear infections are caused by bacteria, viruses and fungi. Treatment varies depending on what germ caused it, and if it is a middle or external ear infection. A repeat examination by your doctor can identify appropriate management. Sometimes tympanocentesis and culture help in selecting the proper medication to treat it. If a virus is the source, no medications are effective-but time will cure.