Here is a bad idea that doesn't work.Big Business aparently knows they do such a poor job of serving their customers that they need a way force you to be their customer.
Many cellular companies sell you a phone and "lock" it to work on only on their service. That is, you can't pop in their competitors sim card and use the phone.
The goal would appear to be to keep you from changing cellular carriers. The result is of course irriated and pissed off customers.
I always though the best way to make and keep customers was to make them satisfied not angry. The phone lock of course serves only to anger customer because for a small fee (or some tedious search on the internet) they can easily unlock the phone and use it with the carrier of their desire.
Locking cellulars to a specific carrier is simply a bad idea to begin with and doesn't work!