FNB Unable to track card transaction refund....

FNB is unable to track refund of funds.

I used my FNB card to pay for Airbnb Accommodation that was subsequently cancelled and money refunded to my card. Nobody at FNB is able to assist.... Not Branch that I visited multiple / Not Forex Dept , I was told to call reserve bank??? Reserve bank doesn't care about R3k refund , Money was paid back to FNB and not forwarded back to my account. Airb BnB provided me with ARN Number yet FNB doesn't even know what it means? Refund was paid on the 06th of June yet money has not been credited to my account

"An ARN (Acquirer Reference Number) is a unique number that your bank can use to track your refund. Provide this number to your bank, and they can let you know when to expect your refund to deposit in your account." FNB Is not capable of tracking it ....