I have covered cakes with fondant thinking it will be used this sunday,alas is going to be next sunday.How can i preserve this cake for a week
I don't think you can. Call it a practice cake, eat and enjoy it. Practice how to slice small servings, etc. Then make another cake.
I have frozen fondant covered cakes on several occasions and they have turned out fine. Just make sure that you defrost it at room temp and don't touch until it is completely thawed. It takes a while.
Tanx,apti,i eventually cut it on sunday and call it national cake to mark my nation's 50th independence