How long to wait before getting more Botox after unsatisfactory results?

I had Botox eight weeks ago and unfortunately my usual doctor was away and apparently the replacement didn't look at her diagram and notes. I usually get a very nice eyebrow "lift". This time I actually got drooping on one side and zero lift. I went back and was told she had "de-spocked" me and there was nothing that could be done. I am wondering if I am going to need to wait until the Botox is completely gone or if I can now get some Botox to lift my eyebrows. Thanks!