Wrong product delivered

Hi,
I ordered for Sony BRAVIA KLV-32R412B 81 cm (32) WXGA LED Television and paid the amount but they have delivered Sony BRAVIA KLV-24P412B 58.8 cm (24). Instead of 32inch they delivered 24inch.
Now I requested for return of my product and refund the amount which I paid. But they are delaying the process.
Would like to request you please take necessary action and help to receive my refund amount on time.
Complaint Request #11753818.

Thanks & Regards
Sudipto Dey