Dell India — dell inspiron purchase issues

I am a tech savvy guy. This is my 6th laptop. Purchased a laptop under the offer bundle along with headphones and initially it was shown in the bill but later bills did not mention it at all. I have registered initially before purchase and bought the item under the account but the item never appeared in my account.in fact there is no electronic tracing of my purchase at all from my side except for invoice showing without offer. They have instead sent me a pc bag i think. I wanted to cancel the order the next day but they say it would incur 15% penalty for their expenses but the order arrived after 10 days without tracking number.

The whole process with dell is unexpected. Every transaction they are making sure is untraceable and there is no evidence to fall back. Horrible customer service. They did not respond to my two written complaints even before the laptop arrival. This is a serious scamster company, indian branch at least. Stay away from this of any type of transactions.