Celkon — Model campus q405 - software malfunction

Address:

Bangalore, Karnataka, 560064

I bought the phone in the month of march. After 2 months i used to receive many pop-up ads, unable to close the pop-ups. The ads (Apps) will install automatically even if the pop-ups are closed. Many nasty apps are been installed and also automatically gets installed even if it is uninstalled.
Took backup and factory reset the phone, continuous pop-up error message is being displayed "unfortunately, wt service has stopped" cant even close the error message and not able to use the phone.
Kindly resolve the issue.