As long as you have access to the database it sits on you don't need to modify the web shop in the slightest, you just need to hardcode a brand new page which interacts with the database to do a count for you, literally all you need is the database credentials to connect with, that's all. All that requires is understanding the back end schema, what tables are in there and where the data is stored, then how to join the tables to get the information you want. Even if you had no idea of the web shop schema you could infer/learn it in like 30 minutes, most systems like these even very old ones tend to have pretty sane schemas that are easy to read. Remember all you're doing is doing an SQL select which is counting the results of a query, you're not integrating, updating or changing anything in situ, you can do a completely new page in the account section for this easy.
Yeah I mean this is the kind of cycle you'd have for some new major uodate to ensure it rolls out safely. But you don't do that for a single new page which has a single feature which is simply a text field that is the result of an SQL count on the database. Just can just write that, dump it into the account page and you're done, no need for a release window or a user story, it's pretty much the simplest feature a web dev could ever write, to return the result of a single query to the screen.
For the record, I am patient, I've not bothered CS other than to have the address changed on my preorder as I was rushed to hospital for an emergency operation and ordered the card to a friends house while recovering on the ward, luckily now I'm out. But many people have done, some claiming they'll call or leave web notes every day until they get an answer, so it's kind of in their best interest to sort this out ASAP, if nothing else to give some relief to their CS. This isn't my first rodeo, I've been buying video cards for 20 years, I can wait, it's just my experience with development tells me that this is a really trivial thing. Maybe there is some really obscure problem stopping them from doing it, like some kind of licencing thing...I just severely doubt it.