Reliance Trends - Worst customer service at Trends Rukmini gaon Guwahati

With due respect, I went to buy some clothes for my daughter as it was her Birthday. At the billing time, I was asked for mobile number. I said that I don't want to give my mobile no at all. But, the man at the billing counter started arguing with me and said that, I have to give the mobile no or else, I won't be able to exchange in case I have to do so. I got bit irritated and thought to record what he was saying. But as soon as I took out my mobile from my pocket, he forcefully took my mobile and threatened me. What kind of customer service is this? Then he asked me to go to a corner room and till that time he didn't give my mobile back. Finally, talked with the manager but unfortunately instead of providing good customer service, he was also supporting his stuff, it's totally wired :-( As a customer, I have the ability to tell that I don't want to give my mobile no and none can force me for that. Then, how come employees at Trends can do that? Even that, how come they can threaten me and take my mobile? I won't ever visit Trends store in my life again if this situation is not fixed. And, I have evidence which I am going to upload in next page.