Ridiculous service

I had a mysterious case of 500 MB disappearing in 12 hours, despite the fact that I didn't change my settings and restrictions for the last 3 years since I started using my phone. I called and explained to an agent and was promised a call back in 30 minutes. It never happened. So 5 hours later I called again and a lady spoke to me so rudely and didn't give me a chance to even explain. Is this really the experience I'm loyal to??