extra tv box

I have had one 360 box and one mini 360 box since my package changed last year. However, my bill lists me as having the 360 box and mini box and an Extra tv box. I only have the two boxes not three. I am concerned that when my contract ends, I will be expected to return three boxes. my previous package did have three V6 Boxes but these went back to VM when the engineer installed main 360 box and the mini box. We did have three sons living at home years ago but when they'd all moved out and the contracted changed it made no sense to have three boxes for two people!

I did try to get this clarified last year but my monthly bill still shows 'extra tv box'. The billing page is not helpful and there seems no way contact anyone about it. Telephoning last year did not sort the problem and I remain uneasy that VM will be charging me for a nonexistent third box!