its a big issue i have with bitcoin. no charge backs makes it easy for you to get scammed and the scammer gets away scott free.
That is where escrows come in to prevent you from getting scammed, Use escrow and make sure you are using a good escrow. You really can't blame bitcoin for this because companies like paypal are much easier to use their chargeback feature and scam people, That's the whole point of bitcoin, To have no chargeback and be decentralized.
Simple, implement a unique smart contract that is witnessless, capable of fulfilling the agreement to transact only upon some certain required conditions being met, agreed upon by the two or more parties involved with the transaction. This way, the payment will be negligible if the conditions aren't met, thereby issuing a reimbursement.
Now if only I was tech smart, luckily we have such a diverse community of crypto enthusiasts, someone will certainly fix this issue. I'm sure their are already protocalls out that tack such a problem as this.
Don't you know that bitcoin has escrow protocol? It's not yet implemented but it's there in the design, It just needs some development to have such smart contracts to act as escrow without the need of a third party.