Hi, This is Ramesh.
Please uninstall "PC App Store" via Apps and Features in Settings.
Also, download Malwarebytes Antimalware, run a scan, and eliminate every piece of malware it finds. It also gets rid of all adware and PUAs.
https://www.malwarebytes.com/mwb-download
Note: the Malwarebytes setup may activate the Premium trial (15-day) version. After 15 days, it switches to the free version automatically.