My Mini DV Camcorder has

My Mini DV Camcorder has lines in the video. Both in playback and record. The lines are a still of some video on another part of the tape. I took it in for repair and they charged me for a head alignment. I brought it home and found a note inside from the repair tech saying it was dirty heads. (Now I am wondering if they only cleaned the heads and charged me for a head alignment) So, I try the camera out and there is no difference. Whether I put in a brand new tape and record, or pull an old tape from my library they all show the same resultant lines. I return it to the depot for repair and my wife gets a call from the tech saying it works fine for him there and for us not to use the same dirty tape in it. His accent is so thick that my wife cannot seem to get it through to him that we tried brand new tapes, and even old tapes that worked. Is he telling me my library of tapes from my children as babies is all gone? Am I getting ripped off here, or am I not seeing something?