Driller not working

I bought a drilller at mica on monday and started using it on tuesday when my husband was using it,it would start and stop same time and this happened frequently sometimes it doesn't start completely when my husband returned the driller today 10th March 2016 they told him they can't exchange it and we need that driller urgent that is why we bought one in the first place so now they telling us it must be taken for repairs and they wont give him a new one and we returned their driller before the 7days they should give us a new driller.we only had that driller for 0ne day and whdn we used it ,it didn't wanna work.