Spoilers. Cure for vampirism quest, soul gems for the witch.

[Sir_Greyhawk]

I was going around cities looking for a decent house to buy, when I went to sleep in a tavern because I got a message about leveling up and to my suprise I turned into a vampire...I can see why some people might like it because of the big stat boosts, but I just dont see anything in it so I want to get rid of it as soon as possible. I talked to the mages guild guy, who directed me towards the witch. I got to the witch and she's asked me for grand sould gems, so I went straight to the Mystical emporium in the Imperical city and bought 4 (I allready had one from a previous heist). I went straight back to her and she wont accept them. I thought that there could be two reasons for her not accepting them: 1. She dosent want the stolen one. 2 She wants them empty, because a couple of these stones have souls in them. I think its probably going to be the second one, but that leaves me with the question: How do I empty them? Ive never been big on mysticism, even with my mage.

[Nerevar Reborn]

Argh! I had this problem aswell. She only accepts empty ones which is quite annoying. Search google for a walkthrough or check gamebanshee itself. Most guides should include a where to find guide.

[Belthan]

Unfortunately, there's no way to empty a soul gem once it has a soul in it. (Although there are mods that let you do it if you're playing on PC).