Boat — Airdopes 131 black some weird automated voice

I have been using this for almost a year now and some weird automated voice keeps saying "oops battery low" this issue comes when the airdopes are under 20% charge and even when i charge it to its maxium capacity it drops to 0% within 30-40 minutes while the company and told it will last for 12 hour...and i have put my hard earned money into this product thinking it will last for a year or 2 at max but this is a let down i dont think i will be ever using your products again and would like a refund or repair or replacement cause this is a faulty product sooo please correct this...