Thanks for the replies and info
The lenses are only 5yrs old and they work ok in manual
The 2 lenses concerned are
1 20-200 aspherical if sigma
2 170-500 1:5-6.3 sigma
I am amazed to hear that as any time I called them I get put on to silly music and I have tried several times
In fact I got so annoyed one time and stayed on the line for 15 mins and still got no reply
So yeah be VERY WARY
I would be wary of photobox
1 they won’t answer the phone
2 they only reply to email when it suits them and never when there is a major issue with their work which I found out to my expense