Nothing to stop you buying, say, a big tin of biscuits to take home on Boxing Day - this might at least show that you value gifts as a symbol of affection, without making too much of a 'thing' of it. If you believe that presents show love, you could act on that, and 'pretend' you're OK if you find the gift isn't reciprocated. I've found that doing this can help with the feeling of miffedness, but if you put too much care into it and they still don't take any notice, you might end up feeling even worse. I once spent quite a lot of money on matching but contrasting Petit Bateau (designer, expensive) T-shirts for my husband's twin nephews when we first met them, only to have their mum pull the parcel open, barely glance at the T-shirts, toss them aside and then remark with an off-handed laugh that 'they have so many T-shirts they'll never be able to wear them all'. Of course, the first new baby in a family always has far too much, and if they are twins, they tend to attract even more gifts, but I wish their mum hadn't been so upfront about not valuing even the thought. I'm a little ashamed to admit that I have not forgotten this, even after six years ], and even though the poor girl must have been absolutely knackered. 
Very soon your 'children', and you, will all have aged, and then you will have to put up with them wanting to 'help' you, whether you need it or not - they will know best! Right now, though, I imagine they are taking you for granted because you've always been there for them, and in paradoxical way you can reflect that it's because they know you're their rock. Enjoy that while you can!
I hope this helps, but if I've hit a raw nerve instead, please forgive me ... I hope in any case that you have a very happy Christmas.