Anyone have the same problem as my dog

My dog been struggling for few months with ears infections that constantly black wax coming out from his ears and it smells really bad and i been to the vet with him about 4 times and they giving him ear drops antibiotics and steroids which not helping my dog at tall and spend a fortune there and they still cant help me out so i am looking for some advice or anyone which got similar problem and could tell me how can i help my dog