Consumer Court

You should have with you original bill,warranty card,copy of your complaint to contact center and copy of work sheet  give by them with detail of fault and service done and charges claimed from you,and copy of your complaint to higher authorities.

You may send an email or letter to MD of the company , address of which is given in the product manual/bill supplied by company to you and mention the sequence of events to MD and state that their machine is rendering any service to you and your work is affected and you are suffering losses and ask for rectification of all faults at their cost immediately .MD of the company should provide relief to you.

Submit your complaints in writing and under receipt.

You have the option to file case in consumer forum.

Do you have any proof for contacting that HP service center?

Have you taken printer to service ?

If you have above particulars, then you very well can contact a lawyer and issue a legal notice

Yes Sir, I do have the Original bill and the complaint no, as HP provides the complaint nos only, and my printer is on warranty period, as i said they are not sending any engineer (as per the purchase bill they suppose to provide onsite service for a period of one year) so i don't have any paper evidence supporting to it, Yes I have one E-mail ID of HP esc.helpdesk@hp.com, on this mail i have forwarded all of complaints. 

please guide me what to do.

send other email and a letter through registered post that the defect need to be cured within 10 days of receipt of email otherwise legal action will follow