Accidental Bch transaction

[nonsisamai]

Yesterday i was depositing 0,1 bch to test the address on Cryptopia.co.nz  before to send all my funds to it. So after copying it from Cryptopia website to my nano ledger, i was confirming the operation being carefull about the recipient address and the amount ( 0,1bch) on the display of my laptop.
After 1 minute i find out that the amount wasn't anymore 0,1bch (!)  but 6,15bch and there were 2 address in one transaction with the 2 different amount sent, 0.1bch to the cryptopia address and 6.1519bch (that is exactly from my history, last amount that 15 days before i withdraw from another exchange to nano ledger!) to an unknow address.
How this could happened? Can i still have a chance to have my coins back?

[Xynerise]

Could you post the transaction hash?
Are you sure it's not a change address?
Bitcoins exist as UTXOs and you can't spend a part of a UTXO, you'll have to consume all, meaning if you received 10BTC --or BCash -- in one transaction and have to spend 0.001BTC, you'll have to spend the whole 10BTC, while the rest will be sent to another address controlled by your wallet.