Classic hasn't been updated in a LONG time... and as such, it's maximum "default" fee is really low by todays standards...
If the transaction is still showing on block explorers, and the fee was > 10 sats/byte, hit up the
ViaBTC TX Accelerator to try and get it confirmed. If the transaction has been dropped from the network (ie. it isn't showing on ANY blockexplorer) The coins should have been returned to your MultiBit Classic wallet.
If you really need to get them out, you could export the keys from your MultiBit Classic wallet and import them into a new Electrum wallet (select "Use Public and Private keys" option when creating) and then send them from that wallet to an address in your main Electrum wallet with "proper" fees.
Complicated and annoying, but with the current state of the network, anything you do with MultiBit Classic is probably going to get stuck