Milton — Flask doesn't keep water warm

Address:

Plot no. 14/12/2,old Delhi Gurgaon road,Opp. Heera Public School,Samalkha,New Delhi-110037

This is to bring to your notice that my Milton water bottle does not keep water warm for a longer time, not even for 3 hours.
I purchased it from a local shop in Gorakhpur, UP named Megashop. It's been 10 months since the purchase. The bottle is used only twice and is in perfect condition as it was bought.
The product details given is:
M158009
HH_U_T_FLASK-POP
MRP 924(incl of all taxes)
Marketed by Megashop Retail LLP
Plot no. 14/12/2, old Delhi Gurgaon road, Opp. Heera Public School, Samalkha, New Delhi-110037
Ph[protected]
E-mail:[protected]@megashopretail.com