Mustard oil without mustard!

After staying in the USA for some time, I came back to Dhaka recently. One day I asked my cook to buy puffed rice (muri) and a bottle of mustard oil from the shop because I was longing to have muri with mustard oil which was unavailable where I used to live. My cook bought muri and the mustard oil but to my surprise, I found the oil to be flavoured with pepper only and not mustard. The oil is produced by a well-known business group of Bangladesh and you all will recognise the organization if I name it. I would like to ask them: how long are you going to cheat people? People buy your product with their hard-earned money; they don't deserve your cheating in the name of business.
Humayun Hyder
Zikatola, Dhaka