I'm here!! My computer has had a bout of flu or something and hasn't felt up to doing ANYTHING! It seems to feel better now though.
First of all the age of your dog is not a barrier to retraining. It is a question of dominance and finding the right motivation for your dog to respond to. Practice, practice, practice in short sessions several times a day and keep your enthusiasm as high as possible. In other words - fake it! Training sessions are the most enjoyable exciting thing in your life and only get better when the dog obeys. Food, toys, high pitched voice, cuddles or a mixture of them can be used as rewards. Your dog is not a trained dog if it ever fails to respond to the recall. Try going back to the basics with true enthusiasm. Once your dog understands a command don't be afraid to correct disobedience.
Secondly try lots of free running and playtime with other dogs, either in a fenced area or an indoor barn. Excersise is important and so is free time for a dog as long as its mind is occupied at training times.
Thirdly either keep your dog in the house or in a run with a roof.If the dog is a digger put paving slabs in the run. This is only an option if the dog is getting plenty of excersise and training. It is vital that you ensure the dog is safe and can not escape, your dog only has to find a friend to play with or a cat to chase and it may roam into an area that it can't get home from. Add to that the risks from traffic and concerned members of the public and you risk losing your dog every time it is out of your control. Remember also it is still your responsibility even when out of your control.
Put simply train your dog, it can be done. An older dog with a stubborn streak is my favourite! They are a challenge and once you have their respect and attention they are so rewarding! A good training calss is a good starting point - remember to practice what you are taught at home as well. And only leave your dog in a safe, enclosed run or in the house.