Sending Bitcoin to Bitcoin Cash address. Restore without private key I need help.

I use blocktrail.com for accept payment in my site by bitcoin cash.

Steps: 1. Generate bitcoin cash address 2. Sending bitcoin cash to generated address

One of customer sent bitcoin (BTC) to bitcoin cash address, and the address is available. Look at https://www.blocktrail.com/BTC/address/35HSWxagkcWxsEgDh3EWE6A1n3THyM1mqC/transactions

Question. How can I get these bitcoins?

I haven't got private key from bitcoin cash wallet, but I have got restore-file "Bitcoin Wallet Recovery Data Sheet". I guess that file can be use to restore only bitcoin cash wallet.

Any ideas?

Thanks
Try tell him to import the bitcoIN cash wallet private key into a regular bitcoIN wallet. If the person does not have the private key nor it not working then the fund will permanently loose

If your using the provider then contact them and they should able to recover it for you