OnePlus India — Not refunding

I ordered Oneplus bud z on 23 June 2021 at 09:50 Am. Payment was successful for order no M[protected].
At 11:30 Am on same day it was showing as order cancelled.
On contacting Oneplus many times, call executives were giving vague excuses like
1. Payment is not done
2. Contact your bank.
3. Contact PayU for refund as Oneplus is not responsible for refund.
Till running behind Oneplus India for refund.