Play store can't normally be removed unless root access is granted. If you have root access, just properly install the proper Gapps. Gapps are all Google product apps that are preloaded into a single package for that phone. (They must be installed in recovery.)

If you do not have root access, do a full factory reset.

*****UPDATE*****

For those of you that this does not apply too and your phone was never rooted and is doing this at random, and a factory reset does not work you need to flash a new image to your phone. (ive seen viruses that corrupt the stock rom image so the user could not factory reset to get rid of said virus)

MODEL - PROGRAM

samsung - Kies/kies lite

LG phone - LG PC suite

...more will be added, just google