Exide Industries — missing battery from service centre

Address:

713146

I purchased one exide inva master tubular battery from your company on 06.04.2015, whose sl. No.- 1ng[protected] and was given three years warranty. But before completion of warranty period, this product started giveng less back up ie one hour only, which was supposed to give four hours back up.
Then, i contacted seller (Inverter power centre, prop.- hafijuddin seikh, pathak complex, new bus stand, memari, burdwan) but he did not cooperate at all with me.
Nest, i i contacted with customar care. As per their guidence, i was told to contact bandhan battery, memari college more, burdwan. I returned my battery on 24.10.2017 to them and told to enquire after 20 days.
When i went to them i was informed that, same item was sent to asansole service centre but that is missing from that place.
So, you are requested to advice me, which will be next step to be taken in this situation.