That is strange that you haven't had a response. They endeavour to answer tickets within 1-2 working days. Have you clicked into the link that you received by email when you first raised the ticket to check on the status? Sometimes the email notification that you'll receive when Support reply to raised tickets gets snaffled into Junk folders.
Can you post your ticket number here please. Hopefully Peter_IK or Ryan_IK can check up on it for you.
Be aware however, that IK Support do not generally work on weekends and the Christmas period may mean different working hours.
As for getting ST4 as you have just got ST3 in a bundle, this is taken from the product details found here:
https://www.ikmultimedia.com/news/?item_id=6964"Previous versions: Any customer who purchases or receives any version of SampleTank 3 as part of a hardware or software bundle on or after November 13, 2018, will receive SampleTank 4 SE for free at release.
Any customer who purchases SampleTank 3 SE, SampleTank 3 or SampleTank MAX on or after November 13, 2018, will receive the equivalent version of SampleTank 4 for free at release."
Hope that helps.