Metering problems with tamron 70-300 brand new lens

Hi everyone,
Bought news lens today fine until either meter is a problem or the mirror locks up every now & again camera clicks like mad then when you look thru the viewfinder everything's black the the centre of the viewfinder flashes & the camera. Clicks like mad.Done reset taken lens off & put 18-55 & 50-200 lens works for a while then put new lens back on camera clicks like mad again.worried I might bugger camera completely.
Thanks
Gazman

Hi guys if some one does know solution as kit lenses work fine,going on day trip so will only take kit lenses to be be safe
Gazman

Take the new lens back to the shop.

Hi Just to let you know took lens back,may not be lens but camera as Tamron lens worked perfectly on shop body,so getting in a sigma lens &see if the same thing happens if it does then it will be the camera.To get round the problem have to switch camera off,take lens off then start camera with lens off then Switch off re-attach lens,camera is fine.So as you can see looks like camera??????.How fast is Pentax UK for repairs???? Does any body know.
Thanks In Lieu of advice
Gazman

Pentax UK don't repair cameras, they sub-contract repairs to a third party, Johnsons Photopia or something similar.

A repair will take only a few days once your camera is put in front of a technician to repair it, but there could be a long delay depending on work load and availability of spare parts, or at least the right spare part.

BTW: Is that Saltford near Mantchester?

Thanks mannesty no saltford nr bath