UNIT DOES NOT TRACK - NO AFTERSALES HELP!!

sent an email on the 21st Feb- no response. My unit does not work! your afterservice is absolutly useless. no one helps. I even contacted you guys on twitter,said somone was going to call me yet NOTHING.I EMAILED, I CALLED in the call gor disconncted no one calls back. why must i pay for a service i do not receive?