Putting in an SD card made my zedge ringtones unusable and I can't access the pet shop app etc.,
The reason for the trouble is you've replaced the existing SD card without having copied the data. With apps installed on the (original) SD card, those are naturally "gone" as soon as you've popped it out – and did not "magically transfer" to the new card.

What you'd have to do is to first copy everything from the original card to the new one – including the "hidden directories". For how to do that, you might wish to consult How do I switch my Android device's SD card without causing problems?