It happens ))
Perhaps you (as giver) also need to write in support, paying their attention to this problem.

Support answered me:
"Unfortunately, we cannot process a reroll without first having the creator of the giveaway submitting a "Request New Winner" ticket. Once he'll submit the ticket, we'll handle it as soon as possible. If you haven't already commented on the giveaway explaining the issue to the creator, please go ahead and do that so he'll get a notification as well. You may mark the giveaway as "Not Received" in one week."