To defend a chargeback claim on your account, there are guidelines to upload documents.
Proof of Transaction: for example, Proof Of Delivery, Invoice
Documents must be in English.
Acceptable formats and file sizes are JPG, TIFF (max. 10MB) or PDF (max. 2MB).
For best results, the original document should either be A4 (21 x 29.7cm) or US Letter (8.5 x 11").