battery problem in micromax tab p300

Location/place: varanasi ,UP

Name of company/service: Micromax

my self gagan singh from varanasi,here i want to in form that i purches a micromax tab P300 on 23.07.2012.There is a problem of battery in tab.At service center on 14.08.2012 they says that they chang the battery and it takes 8 to 10 days but on 27.08.2012 after 13 days they excuse that unfortunatly they mention incorrect model id no. so he provide new job sheet no. SALUPO33R390 of 27.07.2012.when i talk to service excutive on ph.no.01144770044 he told me that it takes10 to 12 days.today on 08.09.2012 when i again call on 01144770044 service excutive once again says that it is in prossece and can takes an other 15 days.SO, i want an imedeat clearyfication from company that how many more times they takes in this.IT is very reticulous that any one p0urches things and use only 17 days after that it is in service center neary from one month.can i know your responsbelty about costmer cervice.I hope for your imedeate reply. gagan singh,mob.no. 09453357467,[email protected]