Asus — Not giving me refund for faulty product

Address: Mumbai City, Maharashtra

I purchased a google nexus 7 tablet and within a week i realized that it had various issues. I gave it to service center, got it repired but it had the same problems again was repaired and had the same problem. I asked for refund and I was told to get a replacement . when i went to take the replacement, it had the same set of faults so i returned it there and then. Since then I have been contacting ASUS customer support through email and phone for refund as I do not need the tablet but never get any appropriate reply and most of the time no reply at all. It has already been with them for last 3 months and I have spent a lot of time and money running from places to places. Please do something