I`ve purchased enough cheap wine to get my personality down to 20 got to the shrine clicked on the wine until i`d used enough the clicked on the shrine but no good checked on personality still 50, Help please what am I doing wrong

Does the wine stack? I'm not sure the effects of multiple bottles will work, as it is (IIRC), drain personality, not damage. You could try using one bottle in combination with a spell which damages your personality.

You're probably playing in "God Mode".

The wine WILL NOT lower your personality unless you take yourself OUT of "God Mode" (console: tgm).

God Mode suppresses ALL negative effects, like poisons and booze, diseases, etc.

(edit)
You can take yourself out of god mod temporarily, drink the wine, and within 2 minutes (before the wine wears off... plenty of time) talk to the NPCs around the shrine, especially the "main NPC" for the shrine, and then talk to the statue.

When you get the quest, if you want to , then you can put yourself back in God Mode. I would wait around for the wine to wear off fully (2 minutes) just in case of a glitch.

Are you sure it's Cheap Wine and that it has the Drain Personality effect when you scroll over it.

What is your character's natural personality?

You can also damage personality at Apprentice alchemy with a Floor/Leek potion (or other combinations).

http://www.uesp.net/wiki/Oblivion:Namira

It could be simply because you resisted the negative effect of the drink with enchantments. Or, you're using a mod that altered the properties of Cheap Wine. Check it yourself, make sure that it drains personality. And I think that you have to talk to the follower of Namira so that she acknowledges that you're now "Repulsive" before you can approach the shrine.

If you are good with alchemy I suggest that you make some Damage Personality potions. But don't forget to remove the alembic, as it reduces the negative effects of drinkable potions.

I suspect the answer lies in the link provided by hazmick. Cheap wine will lower your personality by 10 for 2 minutes. You can stack up to four of them for a 40 point temp personality drop. If your starting personality is 60 or lower, you can drop it to the quest-required 20 or below with cheap wine. If your personality is above 60 to start, you will need to use another method.