Hi, We are not given information on when stock will be arriving but the day the phones arrive they are put on the phone site. Please keep checking there to see if new stock has arrived.
See here https://giffgaff.com/phones
Potential customers may add a phone to their basket and it may be removed from stock and reserved. These are then held for 30 minutes until the purchase is either completed or the order reservation period ends and the phone is added back to stock. As some of these phones are in such high demand they could only go back in stock for a second before someone else reserves it. If the phone is showing 'Out of Stock' Then its worth checking the stock as often as possible, Press F5 to refresh the page.