Blue Star India — not replacing split air condition

I have purchased blue star 1.5 ton split air condition three month ago the ac is leaking and noise is coming from it and then i have called to the blue star service provider and they tell that our mechanic will come and solve your issue and then mechanic see the ac and tell us the gas is finished we have to fill the gas and i tell him why the gas had finished and i tell him we have purchased 3 month ago then he tell us that this problem happen in some ac and then he fill the gas tell us that next time if the problem come we give youa a new ac and gone and after 15 day same problem coming from the ac [leaking and noise] and them i have again call to blue star service provider and then again he tell that our mechanic will come and solve your issue and again mechanic come and see it"s condition tell us gas is leaking and i tell him why the gas is leaking we have purchased 3 month ago.we have to replace ac and give us new one but he ignored it and again repair it and i have asked him why you should not replacing our ac and then he tell us that next time if the problem we replace your ac and them i tell him when you come previous time you tell us that next time we should replace your ac why are you not replacing our ac and then we can not any thing such a bad service and fooling their customer the mechanic is from skyline enginners