Did Dell give out a bad batch of Office 2013 keys?

Hello all, 

I'm the IT Technician for a small company. In the last month I've deployed 6 brand new E7450 laptops to new employees. We have purchased all of these laptops from Dell with a Dell provided Office key. 

In the last month, all 6 of these laptops have had failed activation warnings when my users try to open Office. All 6 of these users work offsite and and activating over the internet option never works. I have to explain that they need to use the activate over the phone option.

It's becoming quite a problem and I'm not sure what is causing this. I'm assuming either Dell gave out a bad batch of Office keys, or perhaps someone with a keygen program out there has generated the same keys my users are using, and it's deactivating our products. 

Any advice would be great.