Re-Issuing Invalid Tokens Problem

I have a server hosting an API in asp.net (dotnetnuke DNN), where Dropbox is an integral part of the workflow within it and it works in the background. The problem exists in the ever changing tokens. I'm met with a barrage of expired_tokens when it's working as a scheduled event in the background, transferring files and validating integrity of the data. I have tried to figure out how to use Refresh Tokens, to no avail. 

With this website, there is only a single Dropbox account. It acts as a storage bin. Users don't get their own access, it comes from me. However, I am hoping to find an answer so I can re-issue the tokens while doing background processes before the token expires. I have tried

Dim refreshToken = dbx.RefreshAccessToken(Nothing)

and I get response that it cannot be refreshed. I really want to be able to have a token that will not expire. Or a refreshToken process that returns a new token and works.

It's quite frustrating to have to constantly check, as one minute of downtime is catastrophic.