At this point, if your tech people disallow use of that API then you kick this can up to your boss with the statement, "It is not possible to have true real-time data. What is the greatest amount of data latency that is acceptable?" (Bring your documentation of what you have researched.)
If your boss says, "Not acceptable to have ANY latency" then your answer is "Can you please talk to our Tech Support folks about this? It is above my head, authority-wise and for political rather than technical reasons."
In essence, to get past this point you have to make it someone else's problem first to handle (or personally encounter) your company's internal barriers.