Card transaction *****

Went to purchase intimates and was charged twice. Was told the first transaction didn’t go through and they ran my card twice... luckily my phone notified me immediately of the double transaction but they refused to refund me and insisted that the first transaction was declined due to timed out. My bank confirmed double purchase and the store is still refusing to refund me for one transaction and giving me the run around. It’s been 72 hours now and they said the reversal will take place with 24-48 hours