This is a scam. Called locksmith who said I needed a lock mechanism change. Asked me for £560 for a new one, threatened to leave my house unsecured unless I paid. Fitted a temp lock and I had to wait 4 days before he came back to "finish" the job. Replaced it with a rusty mechanism. When I complained the customer services person suddenly became unreachable no reply. Reported to trading standard. Locksmith name was Timi.