Mint Mobile review: Disconnected service upon renewal that was prepaid

When it came time to renew my plan after a 3-month trial period, I decided to upgrade to a 12-month unlimited (not really, 35GB data cap) plan, which is their most expensive plan at $360. I prepaid 4 days in advance of my expiration date & confirmed that they received payment via my Mint Mobile user account. Four days later, my plan did not renew as stated. You cannot actually speak with a customer service representative, so I opened the first of three chat sessions. Chat #1: Agent told me the plan would refresh at a specific time (Pacific time) later that day (20 minute session). Chat #2: After that specific time lapsed, an agent told me he would attempt to refresh the plan manually. After 3 failed attempts to refresh my account with the new plan, a technician erroneously canceled my service (account suddenly expired, unable to make calls or send texts). I still had an active chat session, so I asked the Mint Mobile agent why they deactivated my account, and he told me my payment was rejected due to a charge back by my credit card company. I asked to speak with a supervisor, but no one was available, so I gave up (70 minute session, numerous hold times). The next morning, I checked my credit card transaction log to confirm the Mint Mobile charge posted the day after I submitted payment. Chat #3: I asked to speak with a supervisor to contest their explanation, but no one was available, so I requested a callback (20 minute session). A technician (not supervisor) called me & emphatically stated that the charge back error was on my side, but I said I confirmed via my credit card account online that it was definitely their problem. The supervisor told me they would work with me only if I submitted written proof from my credit card company that they made no charge back (20 minute call, technician was not helpful, no resolution). I called my credit card company, their CSR verified they did not issue a charge back & I opened a dispute to get my 12-month charge refunded. I have a transaction history from both sides, so I have proof for a valid dispute, but I will have to fight to get my $361.44 refund for service not provided, plus I lost cell service for at least 4-5 days until I can get a more reliable wireless provider & they lost a customer for life. Mint Mobile customer service is absolutely awful, does not admit their mistakes & will do nothing to satisfy the customer (I.e., me). AVOID MINT MOBILE OR THIS COULD HAPPEN TO YOU.