Voltas — about your after service

I purchased a voltas split ac from simran electronics patiala on 12-5-14. I request for a service of ac on 25-4-15 on which service center acts today i.e. 26-4-15 Two technicians came today but their behaviour was not appropriate & they didnt service ac properly first n then they arrived by saying to came after 10-15 mins but didnt came after then. I am very disappointed after this kind of behaviour on behalf o[censored]r company. I choose voltas while purchasing ac bcoz i have a great faith in brand TATA but today i am very sad on my choice. So plz take further serious assistance in this matter and make our belief continue more stronger on this great indian brand