I have noticed that Moto Service Area’s , when you pay for parking and have the meal voucher included , they do not tell you that if the restaurant is closed , the £9.00 voucher is only worth £3.99 at Burger King , unless you eat what they have on offer that day , and then its worth only about £7.00 .
I have noticed that a lot of Moto restaurants are closing round about 19.00 hrs to 20.00 hrs , ie Kinross , Wooley Edge and some more , I dont think after a days work we need some school boy to tell us what we are havingb to eat .
You could always use it for breakfast in the morning 
Try moto castle donington £9.00quid voucher they have a harvester restaurant plus all you can eat salad bar nice meals £2.49 unlimited drinks. best moto food I found.