i dont receive the gift card wallet code and on other sell want cancel gift card..

I have two situation here:

1- I have purchase steam gift card but the seller not send me the code.
Order ID : 5bbba448-78d4-468e-9eb8-31f904d95e98
2- I just buy 20 cad gift card for 16 usd at 8 May 2018 but i want cancel my purchased and the gift card are still on hold in gameflip market. I have asked the seller he have no problem with it. Can you check it for me?
Order ID : 9792e2a8-b315-417f-b83f-552c02474d45
My invite code TU4K4T