Suggest Treatment For Seroma On The Thigh

Hi, I fell off my bike over 3mths ago and have developed a seroma on my upper outside thigh. I have had it drained twice and also had 50/50 saline and peroxide put into seroma pocket. That has not helped and not only do I have the seroma but the area around is swollen. Not sure what to do next or what kind of Dr should I see.