You would be best not to pull it and treat it with a weedkiller. Glyphosate based one. If its not near any other plants then you can spray carefully. If its growing in between other plants then I would mix some with wallpaper paste to make a gel and either dab it on with a small brush or use a rubber glove with a cloth one on top and dip and rub onto the offending vinca. You might have to do it several times but it will get to the route of the problem so to speak.

ty.what a brilliant idea

Tackled this problem many times and by far the best way is to get the grubber on it, I always start by using shears, cut all that long growth back, rake it out, then grub it out, then with border fork, carefully dig down and ease out near to plants, any plants that can be lifted, then this will make it easier to get out, then keep an eye out over the coming months for any bits that come up, I find it easy to do, like I say some good old grubbing and elbow grease will work wonders.

ty so much,thought it was so pretty then turned into a nightmare