ZTE 831 (II) sync issue

hello guys,

i have recently got my ptcl 1mb connection here in faisel town , lahore . acha the ptcl guy gave me ZTE dark blue one chinease. ok now before i ordered i personally installed a new copper line from line man and there are no noise issues. after patching of modem was done i am constantly having sync issues with the modem and no setting seems to be working or making it stable, used splitter and did connect directly any ideas. i will complain but i can't make any sense of it. if the phone line is new, clear, jointless it should be stable and the exchanges harldy any distant either. what could be the problem. also i tried all modulation setting G.mt, ADSL2+ etc. nothing making it stable .

? any ideas any help will be very thankful