So you've made a Capricorn man angry. You've irritated the goat! This is not an impossible situation, but you have to remember who you're dealing with, and you'll need patience. Just remember, it's hard but not impossible.
Apologize, sincerely and completely. Be honest, but also be reasonable. If you had a good reason for what you did, say so. If you don't know why you did what you did, say that.
Give it a few days, then call just to say hello and chat. Ask how they are doing, and just do some general chit chat. Keep it light and pleasant for a few minutes, then get off the phone. Continue in this way, calling once or twice a week.
If you see something that you think your Capricorn male might find fun, funny or interesting, save it for them. Make sure they know that it brought them to your mind. Don't spend a lot of money on this. Most Capricorns are frugal, and appreciate that quality in others.
Fix a nice meal, with his favorites, but also with one or two of your favorites. Make his favorite part of the meal something he will love. That may be dessert, but it could also be a special kind of bread, or his favorite meatloaf. Most Capricorns are suckers for garlic, so try garlic mashed potatoes with that meatloaf!
Be honest, but don't fawn and fuss over him. He appreciates honesty more than fake sentiment.
That's all there is to it, really. He will come around, you just have to wait until he's ready. Just don't try to butt heads with him!