transfer of bitcoin from bitcoin cash wrongly. i have exchanged my bitcoins with btc on koinex the transiction is done directly from bitcoin to bitcoin cash using destination tag of bitcoin cash  instead of selling the bitcoin and purchasing bitcoin cash, the status of the transiction is showing completed but i have not received in my bitcoin cash wallet. both the transiction is perfomed on koinex. can i pullback the transiction. i have also contacted the koinex customer care there are sayig transiction is sucessfully completed at their end.
As far as I know that any transactions that are in the blockchain cannot be undone so if it has confirmations then you lost the coins