help with HD channels f5s

Hi there hope everyones well,

I need a bit of advice if anyone can help me,I have a sky f5s box with supposedly 12month gift on it,I bought the box back in march,now the HD channels are dropping off one by one with the scrambled sign.

I have done a satellite search to try get them back but all I am getting is failed on search 70,77,78.

Any help would be very much apprichated