Hi Boom Shakthi,
that is bad enough to hear. If possible, you should consult a lawyer and let him/her write a letter to them on your behalf, in which he tells, that you want your money back, asap... maybe this helps - you have rights as a customer...
Anyways, I´d highly suggest you look into the MIDIbox line of SID synths. The best SID synths you can get on this planet! :)
Many greets!
Peter