GSM phone unlock/unblock
I know that in the USA, if you are a customer for at least 3 months you can ask your provider to provide you the "Unlock" code, and they will do so. At least, this is the case with T-Mobil. I just did it with a new cel phone that nobody here in the DR could "UNLOCK". They sent an email to me with the code and instructions for my particular phone and I did it myself.
Careful about taking a good/newer cel phone to a repair/service shop anywhere in th DR. They have a bad habit of exchanging part from your phone, in particular, the battery. Good batteries are swaped for weak one all the time without the customer being aware, till it is too late. It is just the "dominican way" of doing business. Buyer beware...