I bought this pair of shoes in a hurry on the way to a job interview two years ago, and haven’t worn them since. I now have occasion to wear them more often, and it turns out their fit is terrible. They are okay for the most part, though I slide around a little bit inside them. But the worst thing makes them almost unwearable. The back of the left shoe digs directly into the skin over my achilles tendon with every step I take. By the end of the day it’s rubbed raw such that it severely stings to even touch the spot gently.
A folded up bunch of toilet paper placed in the area fails in three ways–it just falls out pretty quick, it’s visible, and doesn’t really stop the digging from happening anyway.
I think this may be a lost cause, but do you have any ideas?
I’ve had a couple pairs of dress shoes that were a little bit too large, and then had a pad put in that attached to the underside of the tongue. That makes it fit a bit more snug. In your case, it might be enough to keep the back of the shoe from rubbing against your heel.
If the back of the shoe is sliding up and down, there are stick ons that go inside the back of the shoe. They have kind of a corduroy texture. A thick insole insert or one of those rubbery heel cup inserts could help.
If they are quality shoes, you might try a shoe repair shop. Possibly they can do something about the part that digs in.
Doubling up your socks costs nothing, so also worth a try.
In the foot care section of the drugstore you can get adhesive insoles that are like very fine sandpaper that go under where the ball of your foot is. They are meant for women’s heels, but I don’t know why they wouldn’t work for men’s shoes, too. You can also get adhesive moleskin to stick to the part of the shoe that rubs you heel. It can be cut to fit where you need it and replaced when it gets worn out. (it’s not really made from moles, it’s synthetic suede. 
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What kind of shoes are they? Loafers or oxfords? If they are loafers, they are not supposed to be tight and your foot should slip up and down in the shoe. Sounds like a poor construction if the leather is poking you in that one particular spot. If you paid less than $150 for them, I would trash them and get something new. If you paid more, AnaMen’s suggestion of taking them to a shoe repair place is a good suggestion.
I second the suggestion to get some heel pads from a drugstore (some grocery stores sell them, too). Also, I did a quick search on Amazon and found a “Fit Right” kit – several different types of shoe pads – that might help you.
If the suggestions don’t work out, ditch them as soon as you can. Life is too short to put up with uncomfortable shoes.
Get two or three thick cardboard beer coasters, cut them down so they fit, in the shoe, under your heal. This will raise your foot up such that the banding will hit the back of your heal in the correct spot, voila, problem solved. The beauty of the beer coaster is the heat of your body will mold it perfectly to fit.
Learned from another server early in my career, successful on every try!