Checked Baggage

I booked online through Qantas and was redirected to Jetstar. I paid for checked in baggage as it appeared I only was entitled to 7kg carry on. When my flight itinerary came through it was from Qantas which showed it
included 20 kg of checked in baggage. I contacted Jetstar and asked for a refund or a voucher for meals and was offered neither. I was told no refunds were available on baggage. Not impressed!!