Sony Ericsson — complain of dealer for taking extra price

Address:

Lucknow, Uttar Pradesh

i buy a sony ericsson phone j105i naiete from g-17-18 ground floor sri ram tower ,13,ashok marg lucknow
tel: [protected]
with price 6400, just after buying phone i asked price of this phone in another shop, and the real price of the phone was 5700
then i went back to the deelar for confirmation then he avoid me for listening a single word,
indded he cheat me by taking 700 rupees more

sir/mam please help me