Hello and welcome to the forums, Sorry to hear about your Pleos problems, I think we can get a better idea if you were to post a video of your baby walking.

Like the saying says, " A picture ,or in this case, a video is worth a thousand words". A short video of thirty seconds or so, long enough to see her walking and dragging her tail will suffice. Does she have any tail movement at all, did she ever?
Did you buy her new, and if so from where? If on Ebay I do not think you can get much help, but if from PleoWorld , Robot World or Accessory Jack. or similar, she should still be covered under 90 day warranty. If so, I would return her ASAP, so they can either fix her if possible or replace her. If she is brand new, I know you are attached, but it could be more expensive to try to fix her yourself or to deal with an issue that may not even be fixable.

this is why a Video is so important. I am sure there are other people here who would love to see this video and who also can give you advice as to what your next plan should be, what they would do if Mimi was there.
time is important so please try to take a video and post ASAP. RWM

and the Pleo Township

of the Redwoods