Kent — Water softener for washing machine

I called Kent customer care for washing machine softener, after 30 minutes I got a call from Kent office, one lady name Muskan from Bengaluru called and said technician will contact.
After some time technician name Salim called and offered one product which has Kent sticker on it,
He fixed that and said bill will get from office, same lady Ms Muskan,
I paid 4800 for this softener,
Now three days over, I didn't get invoice.
Now my worry is the product is original Kent or this people cheated me,
I have telephone number of both Ms Muskan and Technician Salim, if you want I can provide, I need to know the truth, also I need technician to attend to check leakage of the softener.