Elica — Unwanted calls for feedback

Month back i file a complaint regarding the elica product
3 times person need to come resolve the issue again same complaint
After this they used to call from unknown number for the feedback every day i am getting 3-4 unknown calls from elica service center pan india for the feedback
I am not interested in giving any feedback to the company but on calls multiple times i said kindly do not call me again for the feedback but DND and close my case
Again next day i started getting the calls for the feedback
What is the pathetic way to ask for the feedback
None of the staff has manners to talk they dont want to listen they used to speak only the lines they learned
In a busy schedule when you get the calls from the unknown number for the service feedback
What a time waste task

Kindly do not call me again for the feedback