There is not much you can do about alcoholics refusing to get help. If they are family or close friends and you really want to see them get sober, there are not a lot of options for trying to persuade them to do so.
You can take a hard line approach in some cases, and try to intimidate them or threaten them. This is sort of the old school way and represents the old way of thinking regarding interventions. In some cases this probably has worked out, but for the most part there are no magic bullets when it comes to intervening with an alcoholic and there is certainly no approach that guarantees success. Usually if you try to play hardball with an alcoholic and force them into getting help, it will create resentment and they will not be receptive to getting help at all. If you withdrawal support then they will dive deeper into drinking and despair. If you threaten their existence then they will simply sink lower in self esteem and continue to self medicate. If the alcoholic is truly in despair and is bordering on suicidal then there is no threat you can make that will have any impact at all. They are slowly self destructing and there is nothing you can do to pull them out of it.
Now you can still encourage them and urge them to get help and offer to take them to rehab of course, but do not expect them to take you up on the offer. It is still important that you tell them that the offer is available. At some point, a switch is flipped in the mind of an alcoholic and they will surrender and become willing to accept help for their problem. You want to simply stay ready for when this flip occurs. What is your default response for this moment? What is your number one game plan for dealing with their decision to suddenly want help? It should be clear and decisive in your mind and if it is not then you need to come up with a plan. The best plan is usually to get them into rehab as quickly as possible. There they will have the best chance at capitalizing on their decision to get sober and to start making a new life for themselves.
Now you have to stay clear about when they really want help. Manipulation can and does occur frequently. Only give help on your terms. If they just want money then they do not want help. They are ready to change when they are willing to do things your way, not theirs.
So if they say that they want help and that they need that help in the form of loaned money, tell them no. On the other hand, if they beg you for help and you offer to help them find treatment and they agree to this without any conditions, you know they are on the path to true surrender. They have to be willing to do anything to get sober, in order to be truly ready.