SU-Kam Power Systems Ltd. — Inverter Back up time is NIL

I have a SU-Kam 1400 VA inverter purchased in Mar-07. Which is not working properly since two months. Its back-up time is not even 30 minutes. I have launched the complaints to their customer care center more than 3 times. Every time the engineer comes at least after two days of complaint launched & after the height of follow up. Does nothing at all. Says your batteries nodes are carbonized. I have cleaned it. Get it switched off by 24 hours. After that it will run fine. When we start it again, the problem persists as it was earlier.
How much I got from it is, like they want to let the warranty period complete by any trick.
Now -- I have launched a complaint no-162100, on 21-July-08 morning. After continuous follow up nobody came till date.
What is the last wayout for me? Should I go to consumer court ? Or anywhere else ?
Pls suggest.
Hope you will help me out soon.

Thanks & Regards
Yogesh Pratap
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