[Q] OnePlus One Boot Loop topic

My OPO is stuck in boot loop. It was not used for around 4 months so I think battery went too low below charge. I tried putting it on charge for 2 days. Still same. I sometimes get sign of "Battery too low. Charge before switch on" in Chinese & English. I raised a ticket they told me to install the software in fastboot but phone is not switching on so I cannot put it in fast boot to install those files. Then customer support told me to put it off charge for 12 hours and then charge for 6 hours, un-plug then plug for one hour or more and switch on but still it doesnt.
Now even customer support is not responding to my mails.

Kindly let me know what can I do to make it work.

P.S: I am not a geek so please tell me procedure which is easy to understand and can me done by anyone like me.