Just wondering, if I pay with interact from the Cash shop is it instant funds? Or is it like paypal and you have to wait 3wks?

Paypal is instant... I think you have it set to E-Cheques. I suggest having a look at your account, maybe it wants bank account details rather than just card (or vice versa). It doesn't matter if the card is linked to the bank account (as in where that is where the funds come from).