Hi Nathan, apologies for the delay in getting back to you.
As mentioned previously, the token use activity for your account history displays no tokens have ever been spent for healing drivers.
Please try to re-install the app, and if on Android, to delete the app's data and cache in your device's app settings menu. It's possible your tokens balance is not updating correctly on your device, which may be why your drivers are not healing when you believe they should be.
I'd like to include why I believe this is the case. In your original post here, it was mentioned your drivers were trained as low as their health could go, then an attempt to heal them was made. At least 18 tokens would be needed to heal your drivers. Before your purchase of the Investment Pack, the only days in the past 30 days I see your account had more than 18 tokens was on:
16 July (19 tokens)
17 July (22 tokens)
By 18 July your token balance was zero after using them to complete building upgrades and the balance did not recover past 18 tokens until the purchase of the Investment Pack.
Just this evening I’ve had tokens taken from me unexpectedly, yet this time I was duped into buying a driver yet the app said I was buying the intended driver...
I believe this is related to the same cause of the problem I mention above. Following the steps I recommend above should fix this issue, as there have been no tokens used by you since the purchase of your Investment Pack.