Help! I've sent ltc to bcc address
I am not sure your money is recoverable, and I don't know too much about the specifics of Litecoin, but I believe there is hope.  First, I think I should explain what appears to have happened (for anyone else who finds this question, since you seem to have a handle on it).

The address you sent to is a pay-to-script-hash (P2SH) address, which according to comments on this answer are valid on both chains.  This does not mean that you sent LTC to a Bitcoin (or Bitcoin Cash) address.  This means that you sent LTC to an identical, yet valid, Litecoin address.  However, this address is not one that currently has a private key stored in your Litecoin wallet.  This is why you would not expect to see the money there.

This means that in theory, you could claim the coins on the Litecoin blockchain by importing the private key(s) that correspond to the address on the Bitcion blockchain...which it sounds like are private keys that you have in your Bitcoin wallet.  I know nothing about the wallet services you are using, but if you can export your keys from the Bitcoin wallet that generated the address in question, and then import that particular key into your Litecoin wallet, you should be able to claim the coins.

It all sounds like this is what you are already attempting, but you are starting by seeding a new wallet.  If this isn't working, it could be because one of the wallet providers is using a non-standard way of generating addresses from wallet seeds.  You may want to try writing some code of your own (using a utility such as https://github.com/prusnak/bip32utils) to generate your own addresses based on your recovered seeds.  This may help you to find the specific private key for the address in question, and from there you can import that key directly into the Litecoin reference client and claim the coins.  This may or may not be worth the effort, depending on how much money is at stake.

Best of luck!