Sue Begg muttered:

I then got in the local pest chap with his strychnine (sp?) worms. They
haven't worked either. A lot of plants have died because of the
tunnelling through the roots and I am now at my wits end. All
suggestions gratefully received.

My Dad used to have a collection of mole traps which did indeed catch two or
three a year. They always came back though. Have you thought about burying
cheap rubber trugs below the soil surface (with adequate drainage holes
punched in) and planting anything special in them?

You could equalise the equation slightly by using the mole hill soil as part
of a loam based compost for your containers, cuttings etc, it's been nicely
fluffed up already for you ;o)