Refund problem

I ordered from Bagallery worth 3500 around 3 months ago. Order was not complete and quality was also not that good. So I emailed them and requested for returning those products. They agreed for refund so I returned their products. It’s been 3 months they are making me fool that there is some technical issue. I requested them to give me a voucher of same amount so that i can purchase something else. But they are refusing it and continuously making excuses for refund.