Does Mitactin Sulfinex work for treating mange?

The old formula worked wonders. I used two jars of it and both times it worked fast. The last jar of cream looked different so I sent them an e-mail and they said it was the "new improved formula." Well the new formula doesn't work at all. I told them this and asked if I could get the old formula and they just said no, sorry. No suggestions, or sorry to hear it didn't work. It was like they just didn't care at all.