How people cheats?

How people cheats through phone?

I was called over my cellphone  from a unknown fancy number.
Hello Sir this is Radhika from Idea cellular! a voice chirps.
Hello! i said
Sir You are our valuable costumer, thanks for choosing our network.
Thanks! i replied.
We want to to honor you , so we have a very attractive plan for you which will give you lots of benefits at minimal cost.
we are giving you a special sim our customer care executive will meet you and fill your details for this purpose.
OK, i said.
Thanks for connecting with Idea.

I cut the phone and eagerly waiting for the executive.
After a hour one boy entered to my office. He great me and introduce himself as Idea fields staff.
i offered a seat to him he sits and starts telling me very cheap deals sim cards. i opted one plan. He was wearing a Idea logo shirt and also give me a form clearly printed idea office address which was enough for me to verify that this fellow was from Idea cellular.

after filling the form he ask me to submit Rs 500 in order to get a new plan. i gave Rs 500 to him he give me a receipt of that.
Then that guy disappear from the office. i was told to call in the evening for activation of the sim so i keep on waiting.

in evening when i called Idea cellular office the customer executive tell me that i was fooled by those guys and they are getting such more complaints also.

I do not have any solution now. This was my story how i was cheated if you do have such stories of being cheated you can share your story in the comment box.