tina wrote:
I am now left with solid & I do mean SOLID :-( CLAY.

If you mean blue-yellow brickpit stuff then you would be in for years
of backbreaking work, although it is high in nutrients the drainage
will be dreadful.

But since you have already effectively gone down one spit, then you are
in a position to import someone else's soil without ending up with a
severely elevated garden. When farmland is cleared for housing the
topsoil is often removed and sold by specialists (round here I would go
to Bullimores, a google search for topsoil returns lots of suppliers)

Go down as far as you can without breaking your back, and discard it.
Try and break up what is left with a pick-axe and get some gravel down
the fissures to improve drainage as far as possible, then buy in
topsoil. Mix it with sand, manure (riding schools can help) etc.

Be prepared to mulch heavily for several years to build up both the
structure and to compensate for compacting - newly laid topsoil is very
loose.

Prices vary a lot - shop around. You can expect to pay between 20 to
100 pounds per tonne, and price is not always a guarantee of quality.
http://www.salvomie.co.uk/garden/offers.html is headlining topsoil
free to whoever can take it away - an offer I have come across in more
than one place.

You stand a good chance of introducing weeds and perhaps pests. At one
time round here we could get free topsoil from the sugar beet factory,
but the farmers have to wash the roots before delivering them now.
People who took the free topsoil often found it alive with eelworm
because beet growing is an intensive monoculture. A couple of years
cropping potato is supposed to "clean the soil" but I think life is
more complex than that. Don't let the risk put you off. Most things
that you might import other people have already got....

Try your local allotment association for advice, including advice on
reputable local vendors.