https://forums.sdn.sap.com/message.jspa?messageID=6936655
Try using FM: SD_PRINT_TERMS_OF_PAYMENT (for SD) and and FM /SAPNEA/SMAPI_TRMS_PAY_GETLIST (for MM)/
They output full text of payment terms.
compare fm's like ME_PRINT_T052
http://www.**.com/forums/viewtopic.php?f=14&t=191036