Metro by T-Mobile

I bought a new phone there couple months ago the employee there seemed new and a stressed because the sms tray wouldn't go in and she kept asking her boss for help but her boss was busy so she just shoved it in there and said it's all "fixed" and sense then I haven't been receiving messages or calls when I went to go get it fixed they said it's been to long and I have to buy a new one I have two job I barley made time to go in I don't see why I should be needing to buy a knew one when they're the ones who broke it