From the article it seems like Iron Mountain was doing the actual storage, and OSS was just acting as a middleman and taking some money off the top.
To be somewhat fair, Iron Mountain is just a storage facility. OSS were likely the consultants who worked out how to get the archival data from the station's tapes into Iron Mountain and then get the data back out when needed. So they probably offered a worthwhile service, they just eventually stopped doing it and left the station in a lurch.
And they sent OSS a legal demand letter to keep paying the Iron Mountain bill for their data. If OSS actually was using IM and not just running a scam, then the data should be pretty safe, if just not accessible for a few weeks/months.