Use provado vine weevil killer every 2 weeks from spring until autumn. Kill every adult that you see: they tend to come out at dusk.

I would be a bit reluctant to keep your plants in the same compost if it was contaminated by vine weevil grubs. However, you may be able to clean it enough for re-use. The way I have done in the past was to spread it out thinly on a concrete surface and then went over it with one of the Flame Wand weed killers. Also have used a steam wallpaper stripper to do the same thing. That worked as well.

If the plants have been in the pots for more than one season I'd use new compost anyway. Horrible grubs aren't they?

Spread it out on the soil as mulch and let the birds eat the grubs, they'll gobble 'em up. Avoid Provado type insecticides, they are systemic and will kill everything that feeds on the plants that grow in the soil/compost. I would recommend nematodes for vine-weevil, best to treat late summer but spring is also recommended. Vine weevils don't fly so you can erradicate them in your own garden without many more coming back in from elsewhere.

Thanks every one I think I will replace the soil ready for the spring I am going to put something sticky round the outside of the pots