Compaq R191b, 18.5", LED Monitor found defective on first day

I have purchased a Monitor (Compaq R191b, 18.5", LED) from BRIGHT ENTERPRISE, B/32, CIT MARKET, JADAVPUR, KOLKATA-700032 on dated 3-Feb-2014 (Invoice No. 4986). The said Monitor found defective when it brought into working on the same day. A white spot on screen which is increasing and decreasing on the upper right corner of the Monitor. Company expert said that it is permanent and unrecoverable.
I contacted to customer care several times and at last I got a Complain No. [edited by Moderator]

The Service Engineer (Edited by Moderator) inspected the Monitor on 05-Feb-2014 and took a snap also, but it is yet to be replaced. I contacted to the service center several times but they ignored it. Such type of delay in providing a fruitful solution affecting my profession.