Oh my goodness! That is super weird! I am not seeing any known issues with the LineLink that would cause this issue. Having the device and SIM card replaced so many times should have fixed this by now. Do you have a T-Mobile phone you can try your SIM card in to see if it sees the SIM card? If so, can you place your T-Mobile cell sim in the line link to see if you get this error?
Just checking in to see if you tried Chris's suggestion. Please give us a reply back and let us know. Thanks.
If the problem is happening across multiple devices and sims it sounds like a provisioning issue. I would call into T-mobile and have them look over your account to make sure everything is still set up correctly and try the tests that tmo_Chris mentioned.