When we mark the order as dispatched we know it will reach the customer within 3 days. Looking at the dates you have provided seems excessive delay from the date of order to the date of claim. When the customer places the order they will have a delivery estimate delivery period up to 5 days so when a customer waits a few months it makes me wonder.
When purchasing online I rely on the estimate delivery period and will only contact the seller on the last day of delivery period. I would not wait months or weeks or even years to let the seller know there was a problem with the order i.e not arrived. To me it defeats the object of having a estimate delivery date when customers claims none received order weeks or months later. Naturally on low value orders customers will know the cost of sending the order tracked will not be cost-effective so the advice given by seller support to send everything tracked will not be feasible.
Before any claim reaches A-Z process we would expect the customer to contact us in the first instance, failing this the claim may draw adverse conclusions. If the claim is for loss, damage we follow the courier claims process by either dispatching a replacement or refunding the order. I understand Royal Mail have changed their business terms and conditions from claims made using or OBA. DMO terms were not favourable to the business seller. When we make a claim for loss with Royal Mail for loss or damage they refund in full (Full Retail Cost below £20).
If its a parcel Id rather pay £3 retail cost then £2.60 and get nothing back for loss, this is obviously subject to what you sell below £20.00