Having to go through all this just to get data isn't what we want but I think we can help. What's the error you get when you try using data? Have you tested the data in other areas to make sure this isn't something going on in a specific location?
Have you tried replacing the SIM card?
Good morning, magenta6810118!
Just swinging by to see if you've been able to get data working on your OnePlus 6T. If you're still having issues, this sounds like a data feature may be missing on the account. It may also be an issue with the SIM but I'm leaning more towards the data feature not being there. My recommendation would be to work with T-Force via Facebook or Twitter to have them double check the data feature on your line.