How to allow emails to come through again after unsubscribing via gmail

Question

I unsubscribed to a bunch of emails using gmails unsubscribe feature. One of the emails I unsubscribed to was a load of promotion emails which I didn’t want anymore, little did I know that the same address sends order confirmations and shipping information when I purchase from the website.
Now I do not receive any emails at all from that website regarding my order, even after re subscribing to their mailing list. It can not be solved, I have checked my ‘filters and blocked address’ section in settings which only shows blocked addresses, have checked my spam and bin - nothing.
What a stupid feature to add if you can’t undo it or resubscribe somehow. It seems it internally terminates emails and there’s nothing you can do. Ridiculous
Don’t think there’s anything else to try but all comments appreciated to bring attention.

icantchooseone · Accepted Answer

i got this reply for you from Google
 
Click the settings button in the top-right corner of the screen.
Select "See all settings" from the drop-down menu.
Navigate to the "Filters and Blocked Addresses" tab.
Scroll down and select "Create a new filter".
Add the email address or domain you want to whitelist.
Select "Create filter"
Check the box that reads "Never send it to Spam".
We don't have an explicit way to "re"subscribe to an email since we treat it like spam once the user selects unsubscribe. But the user can whitelist to allow it back into their inbox. Changes usually take up to 24 hours as well if the user follows these steps.