Basically you are lucky that ETH and ETC share the same wallet format. Because you can easily get your private keys from your ETH wallet and import them to your ETC wallet. I don't know which software you are using but you need to find a way to extract the private key, do it in a safe environment, then take that private key and import it to your ETC wallet. To be safe, just make a new ETC wallet after you transfer the funds.
So the coins are not lost but you need to do some technical stuff to get your ETC funds on your ETH wallet. Since you have 4GB cards, you can still mine with them for a few more weeks with lolminer. Basically it works but hashes at slower speeds. I get 27.5MH/s with my 4GB. Search this subsection and find lolminer.