It was a service wallet, not something hardware or software wise I completely control. Not sure if it would makea difference.
It possibly makes a big difference...The important question is.. do you have access to the private keys for the BCH wallet? If you DON'T have the private key for the BCH address, you're pretty much screwed.
You will only be able to recover the BTC, by importing the BCH private key (for the BCH address you sent the BTC to), into a BTC wallet.
If it was an online service (like an exchange or webwallets)... Chances are you won't be able to get the private key... and your only hope will be if the one service can help. You'll need to contact the support for the service you are using and ask them for assistance.
If you do have access to the private keys, then as stated, import the private key into a BTC wallet... And the BTC should show up.
