I have called both my carrier and Samsung about this but did not receive any help on this issue. I bought a Galaxy S20+ off of Amazon and put my carriers Sim card from my old phone into the phones slot; I powered it up but a message from OMADM popped up saying Activation Incomplete Internal error 407 and sometimes service error 605 or something like that. I can text people like normal, my Sims card setting looks good and connected, the data works but I can not make or receive any calls. I've tried shutting my phone down, taking the Sim out, putting it back in and turning it back on but the issue remains; I've also tried doing a force stop and a clear cache while rebooting but it hasn't worked either. Everywhere I look on Google says the same thing but none of the listed solutions are working for my phone, so any help on what could be wrong would be appreciated.