Unable to remove Activation Lock in ABS

We have nearly two hundred devices that we need to migrate to our Mobile Device Management (MDM) platform. However, each of these devices has an Activation Lock enabled, and unfortunately, most employees do not know the Apple ID associated with them. The company previously used a single Apple ID for many devices, and the individual who set this up is no longer with the organization. As a result, we are unable to add these devices to our MDM system without Apple unlocking them first—yet, despite clearly owning the devices (as evidenced by the Apple Business Manager (ABM) records), we are faced with the need to request Apple’s intervention.

This raises a key concern: what is the purpose of ABM if we are still required to provide additional proof of purchase and go through the lengthy and uncertain process of requesting Apple to unlock the devices? ABM already contains all relevant information, including the fact that these devices were purchased from AT&T, but Apple insists on receiving further proof from AT&T before they will proceed.

I currently have around 150 devices that will need to go through this process, but Apple limits us to only three requests per email address. This presents a significant challenge in managing these devices efficiently. I don't know if there is another way to approach this?