Reliance Fresh — Cheated us with wrong billing

Address:

Chennai, Tamil Nadu, 600116

We have purchase BOOST and got an offer for Rs.100 worth free vegetables, since our card not accepted for full bill amount we have returned the BOOST but they have billed for vegetables. We are not in need of vegetables and intimated them to take it back but they refused only because they have billed it.Kindly resolve the issue, we have paid Rs.500 and left all the grocery in shop itself since their response is very unkindly and arrogant.
Kindly help us to get our money back pl.