I have not received the coins yet.

You cannot receive LTC through the BTC network.

how can i recover it back to my luno BTC wallet.

You cannot receive LTC into a BTC wallet. You generally cannot reverse cryptocurrency transactions.

I am not familiar with Luno. If Luno is a multicurrency wallet that supports both BTC and LTC, you may be able to use it to receive your LTC. Hoever it appears to support only BTC and ETH. I suggest you find wallet software that supports LTC.

The general principle is to export your private keys from your BTC wallet and import them into a LTC wallet, then sync the LTC wallet with the LTC blockchain.

I don't know how closely aligned LTC and BTC are, it may be that LTC doesn't support all the address-types supported by BTC - if so there is a chance your LTC are lost - or need more complex assistance to recover.

Remember to never give your private keys to a helper. Never give a helper passwords for or access to a funded wallet.