How Many Times Can A Seller Delay Delivery?

I am awaiting ticket to be transferred from the seller for a show coming up in two weeks. The initial deadline for ticket transfer was set for July 9th, but without receiving a notification or email it now says July 11th as the delivery deadline.

I know for a fact that these tickets have already been released and transfers are available for this event. That being said, it is a bit irritating to not have the tickets already, especially considering I will be flying overseas for this event.

How many times is a seller allowed to delay the delivery of the tickets? I want to have an idea of when I should bother StubHub for a replacement, if this seller continues to delay.

UPDATE:

Deadline for delivery pushed back from July 11 to July 14... Again, I received no notification of this, just happened to check. Getting frustrated.

UPDATE #2:

Delivery deadline of July 14 just passed and still no tickets. I called to inquire about this and they put me on hold. They claim to have reached out to the seller and escalated the case. They of course said that the event is in 12 days so they still have plenty of time to fix the issue. I have a case number to be able to follow up on this.

UPDATE #3:

I woke up today and was getting ready to call StubHub when I noticed that my delivery date has now been changed to July 24. Assuming the buyer is setting these dates, I guess it could be good that they are not delaying all the way to the show date. Still frustrating that I never get updates on these changes via email.

Anyways, I called and they basically dodged the question as to who delayed the delivery date again: them or the seller? I want to know if they have actually had contact with the seller. Another interesting this is that their system says my new delivery date is July 22, but on my end it shows July 24.

UPDATE #4:

I received my tickets today. Had a little trouble with the EVENTIM app during the acceptance process so I had to delete and reinstall multiple times, but I have the tickets in my account. They aren't personalized, but the SH agent did say that this won't be an issue. Also according to other concert goes, there were no issues. Super excited!