faulty watch

purchased a guess watch on may 2016 and it gave me problems from the 4th month of sale.it was booked 2 times for repairs but still gives me problem and the other challenge cant be attended by the store as i was told 2 times by the staff memebers that i should replace the battery with my own cost since the supplier will charge me.my challenge is i expected a better quality from the brand and even though one of the problem might be the battery i expected a better quality from it since the watch is still under a 2 year guarantee