How many words are in the mnemonic? Different mnemonic schemes will have different mnemonic lengths.
There are really only two possibilities here. You could either have an Electrum mnemonic, or a BIP 39 mnemonic. You should try restoring the wallet with Electrum and MultiBit HD.
12 words. I will try the 2 you suggested. Wouldn't be the first time I was scammed (or the last).
