i need my money back

i made an order with herbalife in april 2019 and i unfortunately put in an incorrect order number and then decided to cancel the order and request a refund. i requested the order they then said they would cancel the order and refund me, they requested my banking details which i then gave and i was advised that the money has been refunded to my account. i waited for about a week and a few days and then decided to contact them to let them know that nothing has been deposited to my account and i have been ignored ever since. its been a week now