Jabongworld.com / Refused to exchange

I have purchased a Kurti from www.jabongworld.com and it was very lovely. Quality was great and it looked exactly like pictures on their site, but there was one small problem, it was too large! I immediately contacted customer service and they said that was possible, because sizes may differ according to suppliers. That actually made no sense to me. Then I asked for an exchange and they said they don't do exchanges if the products has do defects. When I asked them so what am I supposed to do with that Kurti they said "we have no idea". Terrible customer service! I'm extremely disappointed.