Waterfield executive leather messenger

WaterField Executive Leather Messenger Bag (full size) for laptop work and travel.  Purchased here https://www.sfbags.com/products/executive-leather-laptop-messenger?srsltid=AfmBOorOKTgNybpAU6WDLvo45kWCJjxjNiDU5c1aSEXhq-Jvxj91ZjU1 Chocolate leather Full size version  Has custom interior water bottle sleeve sewn in by company  full grain natural tanned leather  padded laptop sleeve and iPad sleeve  Leather grab handle on top.  Back sleeve for secure fit on travel suitcase  Dimensions are 15in x 3.25-3.5in x 12in 3.5 lbs  Volume 10.5L  Purchased about a month ago brand new and used it a few times only for travel and to office.  Beautiful bag but I need to switch to a backpack because of back issues.   I can’t return it because I asked them to sew in a custom water bottle sleeve Retail is HKD3700