Life note 3i left mic not working

As of within the last hour my left headphone just lost its mic idk why as why it happened since I’ve just been relaxing in my room talking on the phone and it suddenly stopped working I noticed bc I was using one ear bud at a time and the person on the other end couldn’t hear me anymore. Sadly I lost the receipt and idk what I should do or if there’s a way to possibly fix my issue I love these headphones and I’ve used them for hours everyday and usually use the so much I swap ear buds to keep a full charge all day so if there’s any way to fix them please let me know. Thank you