U1579530167312 , via OnePlus 6T T-Mobile , Jul 25, 2020 : Like many others, my 6T had WIFI and Cell dropped calls along with not being able to update to latest OS. I bought the phone on Amazon as a refurbished unlocked phone. My carrier is Republic Wireless. As with other threads, I began with contacting service support. I knew I didn't have any warranty with One Plus. I went through the usual clear cache, resets, etc. After several weeks/ months of this, the agent sent me a link to install on my home computer in order to have service remote to my computer. Then I was to connect phone to computer via USB. I was told they would contact me. I wanted over a month. While waiting I sent more emails to ask when, letting them know I was ready. I finally heard from another agent who began another round of emails, resulting in sending in my phone to the factory repair center. After several days they requested $189.44 USD and I sent payment. 3 days later, my phone arrived, looking like a brand new phone. As I booted it up, immediately I knew something was different when the pink screen emblazoned with T Mobile appeared.. I out my Republic SIM card in and of course it wouldn't work. I used the network unlock app, no luck. I callled and waited forever to talk to service support, three times and was talking to a supervisor ( using my wife's phone) but we got cut off. I began chatting, again waiting long periods to chat. The first agent told me to contact T Mobile and they would help me. I asked, "Even if I'm not a customer?" He assured me they would. I went to a T Mobile store, they gave me a phone number. I called, almost instant response. Agent tried to help, nothing worked, so he sent me to tech support. When they found out I am not a T Mobile customer I was told he could not help me. He said One Plus should make it right. So, back to long waits on chat with One Plus. Agent sent me two technical links to try, I made the mistake of asking him to stay with me will I tried the links. I clicked on one link that essentially told me I had to be a customer of T Mobile to get help. So, I tried to return to chat and couldn't find it So started over, at night, sat in line and was the only one in line and they closed. Next morning began again. When finally got an agent we spent well over an hour and he was very helpful. Bottom line, he told me he and the supervisors were trying to resolve it, and he would contact me in 24 hours via email. From reading other threads I was suspicious of this. At first he asked for 48 hours, but we agreed on 24. It has Ben over 48 hours, and no response. So, I'm dumping One Plus, filing a dispute through my credit card to get my money back for the repair. I am going to put the phone on the market and buy a Samsung.