Last year, I bought a Samsung mobile phone and prepaid service from T-Mobile exclusively for travel. I haven't left town for several months, but I have to take a trip next week, so I decided to add some money to my account. I did that part online, and it worked fine...but the phone didn't. It said "No Service", even though I was getting a strong signal. So, I called T-Mobile, and got transferred...and transferred...and transferred. I was transferred to seven different people, finally ending up with someone in India on a connection so bad that I could barely hear her.
Ultimately, I found out that the account had expired, the phone number had been given to someone else (possibly not even a T-Mobile customer), and the company keeps no record of which numbers have been given to which customers once an account expires. I ended up having to visit a local T-Mobile store, which sold me a new SIM card and assigned me a new phone number. This number is only good for three months, unless I use up the current balance and add more time, which will buy me three more months. The customer service experience in the store was great; the experience on the phone was horrible.