Clogging issues...pro plunger?

At the building where I work we have had constant clogging problems since we moved in a little over a year ago. Unfortunately we then have to walk next door to use the bathroom until a plumber arrives. Normally this takes at least a day so it becomes quite a pain. Our janitor has a plunger that he always tries but it never seems to work. It's the same plunger I have seen you guys post in multiple other posts as the one to get. So my question is, is there a plunger that is even better? Unfortunately there is no option of getting a better toilet since that is up to the company and so far it's a no-go. Thanks for your help!

Is the problem a clog actually in the toilet or, in the line below that toilet...

If it is the toilet perhaps an industrial accident of some sort can ocurr that ends in breakage of the toilet.

These things have been known to happen...

Good thought...I don't know where the clog is (toilet or line). Different plumbers have said different things. Some say it's the toilet, some say it's the line that goes from the house to the street and others have said there's nothing wrong that they can see. Personally I think it's the cheap toilet and the line but that's just my opinion.

Maybe something very unfortunate will happen to that toilet...who knows!

A sledge hammer falling of a ladder while changing a light bulb near the toilet usually works.