mention your car make &Model, CVT is not repairable in Pindi /Islamabad etc, replacing gerabox is good option,before going 4 it you get a throttle body check and tunning, the RPM controll gets Jammed, try high octain a quater of tank followed with norma, consume full tank,
if you have changed gear oil with ATF then stick with it, the best ATF is ZIC,
However a good mechanic i have known but not experienced my self is Samadar Khan near Railway Road saddar , you can have his expert opinion.
Now to share my experience
i bought city 2004 in 2010, after 6 months many mechanics told that the gera box is faulty, local mechanics,honda 3 s shops etc,
ggood luck i got to one who rejected this diagnosis and carried a simple tunning, since then i am driving it ok