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Elavon https://www.elavon.co.uk/customer-centre/setting-up-your-account/chargebacks/chargeback-faqs.html
Chargeback Stages
Stage 1. The customer contacts the card issuer to tell them which transaction they wish to reverse
Stage 2. The issuer investigates the claim to verify what the cardholder is saying
Stage 3. If the issuer agrees they will recover the money from the merchant’s account and provide a conditional refund to the cardholder, and advises the acquiring bank, who in turn advise the merchant
Stage 4. The merchant can review the issuer’s decision and choose to contest it by submitting their own evidence to support their position, for example a delivery signature. This goes back to the acquiring bank, and then on to the card issuer.
Stage 5. The card issuer evaluates what each side has said and if the merchant’s case is considered more persuasive than the cardholder’s they will reverse the conditional refund, concluding the chargeback.
Stage 6. However if the card issuers finds in favour of the cardholder the merchant can pursue the matter further and ask for it to be reconsidered, and provide further evidence if it is available.
Stage 7. The final decision in favour of one party or the other, which is made by the card scheme rather than the issuer, cannot be challenged further, other than through the process of bringing the matter before a court.