Garmin Forerunner 235

I took my original garmin forerunner 235 serial number 4DY529114 watch in still under warranty in April and they gave me a new one under warranty however now only after only 5 months the new device's battery only lasts 1 day . I took it to garmin in Rosebank and they booked it in . I got an email to say they are doing the necessary tests and 2 days later i received my watch with no description or communication of what was wrong as the battery still only lasts for one day. I think this service is terrible and basically Garmin has shown me that they dont care and cant even bother to take the time to inform me as to what is wrong with my device and the fact that this new device is faulty after only 5 or so months is pathetic as i originally spent R5500 and i have had 2 forerunner 235 devices over a year and a half of which both were faulty . I await feedback before i take this matter further.