Sangeetha Mobiles — Payment cheating

Address:

Bangalore, Karnataka, 560075

I've purchased apple iphone 5s 16gb in month of december 26/12/2015
In tyagarajanagar sangeetha mobile store and,
I had cashback of 15% on zopper but ive recived only 10% cashback
When i spoke to the sangeetha mobile regards this and they are telling
5%cashback had already been deducted in the time of purchase
Nobody informed me during the purchase now i called and ask they have al new story to tel m not satifyed with service the store manager dint responed properly to me and he was very rude to me on this note