Thanks for reply. I contacted Virgin through their facebook page, then telephoned. Sent phone off for repair on Saturday morning (16 May) received it back today Thursday (21 May). Extremely impressed with fast service....until I took more photos and find that nothing has changed.
A friend is going to post the pics showing the ZTE ones and ones taken with a sony for comparison to Virgin's facebook page (I'm not that technical and she has been helping me out with this problem.)
Don't know how to post the pics here, but will have a go.