FORT WAYNE, Ind. (AP) — Some patients who had their personal information compromised by a data breach at a Fort Wayne-based medical software company are having issues signing up for free credit monitoring.

Those who have tried to take advantage of Medical Informatics Engineering’s offer say they can’t tell whether the online registration worked. They say they’ve also had to wait on hold for long periods or didn’t receive any help when calling hotlines provided by the company.

The (Fort Wayne) Journal Gazette reports that Medical Informatics Engineering began sending letters to patients last month after the private information of 3.9 million people nationwide was exposed when its networks were hacked in May. The compromised information includes patients’ names, Social Security numbers, birth dates and addresses.

A company executive says officials have reached out to the credit monitoring company.