HandSet Service Complaint

Hi,
I had raised a complaint previously regarding the delay in servicing my HTC desire 600 dual sim mobile handset requesting to either replace with a new handset or refund my money. I had registered the same complaint as guest. After the complaint yesterday HTC service center smsed me that my phone is ready and today I had a chat with customer service executive where they informed that i will be getting a new handset. But they are saying that the new handset warranty will be that of my old handset i.e. 01/02/2014 even though i am getting a new handset on 25/10/2014. So the warranty of the new handset will be 3 months. How can i trust the new handset as my old set has started giving me problem after 4 months. What if the new set starts giving me complaint after 4 months or HTC are giving me a defective handset which will function till my warranty is over.
If they are replacing with a new handset then i want the warranty to be for the new handset not for my old handset which was defective else i want my money back.
Ticket Number: - 14INA380005653.
Dated: - 17/09/2014.
IMEI: - 357209051361091.
I have all the original bills with me.
Thanks,
Smith M S
Mob: - 9980740195