Qatar won't refund money due to me

I booked a flight with Qatar, which subsequently had to be cancelled. They processed a refund for me, claimed to have refunded the money, but after 6 weeks, no money to be seen. I have called them over a dozen times, and each time, get told it's my bank's problem. After visiting the bank, and being told there is no trace of any refunded funds, Qatar STILL has yet to do anything about the missing ticket money! I am tired of dealing with customer service that sends me in endless loops