I had a double mastectomy in March 2012 and I had problems with the incision line healing. They had to remove the necrotic (which is dead) tissue and then close it up again. After having problems with healing again the PA finally removed some of the fluid from the expanders which helped because now the skin wasn't being stretched. She did not add more fluid to the expanders until the incision line was completely healed. This helped me but we are all very different with different issues. I don't know if it would help in your situation. Also, maybe you are allergic to the expander material??? I don't know but I did want to share my experience with you.
I do hope they can resolve this for you. Please keep us updated on your progress.