My first bike was from Sears; the second was from Montgomery Ward. The Sears bike was one of those late '60s early '70s with a banana seat, butterfly handlebars, and a gearshift shaped like one on a car; it was a 5-speed derailer. I rode that to school and to friends' houses from fifth through seventh grade, by which time I outgrew it. I the Ward's bike was a three-speed hub gear made in imitation of an English Racer. I rode that through HS and college and for a couple of years after that. I then sold it when I made a cross-country move and couldn't take it with me and I didn't cycle for a long time after that, indeed not until I was in my early 40s and developed type II diabetes, when I took it up again first for exercise, and then for transportation.
However, both Sears and Wards had service departments; Wal-Mart, Target, K-Mart, Dicks Sporting Goods, etc. do not.