PIP Judge ruling until 4/4/19 but already getting

Went through all the assessments and face to face review got rejected so appealed and won Judge gave the award from 2017 until April 2019.
Received a new form to fill in and return by June which I have done.

Now they say I have to have another Face to Face even though I still have 7 months left.
They told me on the phone they can do this at any time they want it feels like harassment.

Can they overturn the Judges award early?

I am determent to do the face to face and if necessary appeal again and go to tribunal but it just seems so unfair

Anyone else know about this or anything I can do

Thanks
Gary
Feel exasperated