Missing money from my Apple Card

I put in a new Apple cd yesterday afternoon for 100.00 when i was going to bed my account showed 50.11

balance this mornin* I tried to buy diamonds and it wouldn’t permit this ! If you try to buy something and it doesn5 go and I try to do it again I think it’s being charged twice to me but not giving what I wanted. Please fix this. I spend a lot on this and to me 50.00 is a lot of money. Thanks