GSMmonster broken phone Cedarhurst, , New York

I ordered a phone from GSMmonster and was told that it was unlocked and could be used with any phone carrier that used a sim's card.   I was going to a different company but they were sold out of the particular cell phone.  I wish I knew about Rip off before I ordered this jacked up cell phone.  When I turned it on it was Tmobile stuff on and along with a text message that's can't be deleted that shows an error.  That's not the worse thing.  I can not charge the phone with the plug.  If I plug up the USB plug to the computer it will charge the phone but the charge doesn't last long.  I am so mad because I have emailed to no avail.   I received this phone on Friday and wanted to send it back by Saturday.  They charged a 20% restocking fee.  What does that mean do they resale the phone to someone else.   Never and I mean never buy anything on the internet from a company that doesn't have a Phone number.  Please don't buy the Motorola Z3 in black because you may get what I hope to return.  I emailed them saturday and today and will keep doing so until someone answers me.  They only give you a seven day return policy.   They need to be sued and made to go out of business.   If I knew then what I know now I could have kept my hard earn money