my experience of Zoom at thokhar - adjacent to Areeb is quite good.
Explain what kind of issues you got in your picanto ? Is it fuel pump or some pick issue or any thing else ?
If bad fuel has already messed up few things of your car , then first let it done and then start using fuel from some reputed fuel stations.
My List is following (these are equally good)
Total Adjacent to LDA office johar town
Zoom Thokar niaz baig
Areeb Total Thokar niaz baig
There could be more as well but my experience is limited only for the above.in that area