My SO moved her Samsung S8 to Mint during the fiasco that occurred during Dish’s migration to AT&T. After her initial 3-month period at $15.00/mo. she paid a year in advance to keep that rate. When that year was up she paid a second year in advance.
Her $15.00/mo. rate has never changed. She has had no problems at all with the service, probably because T-Mobile provides 5-bar service to her home. She has never traveled outside of a T-Mobile coverage area and doesn’t make international calls.
We have messaged each other about a dozen times daily. On ONE occasion I sent her a message that she did not receive. The day after that happened we sat side-by-side with my phone showing a sent message to her and her phone not showing that message received. We couldn’t determine which carrier lost the message.
She is 100% satisfied with Mint.