Sky interactive cable to telephone socket, How do I fix it? ?

I can't get any interactive services from my Sky HD digibox. I have a loose wire on the cable which connects from my telephone socket to my digibox, I have tried toreplace the wires in the plug without success, each time getting an error message on the TV screen. There are 4 wires inside the white cable, Only 2 are being used, That's blue/white & white/blue, I think, Is there anything that could be wrong? any info available please .