Posted: 06/06/2015 at 12:29
Well, you know best - we obviously know nothing - some of the best gardeners on this forum have given you the benefit of upwards of 150 years of experience but you have derided it.
To explain it very simply - if you use weedkillers at too high a dose you will kill off the foliage but the roots don't die and the plants regrow - as it seems you have found.
If you use the weedkiller as instructed on the packet and then wait for it to take effect the foliage will absorb the weedkiller and slowly pass it back to the roots - in about three weeks not only will the foliage have died, but the roots will be dead also and the plants will not regrow.
However, if the area has been neglected for some time there will be seeds in the soil that will continue to germinate for some time so the area will need treating repeatedly. Also weed seeds from surrounding areas will be blown in on the wind, so you will never be totally free from the need to treat the area from time to time.
If you really want to be able to ignore any need for gardening activity then artificial grass is a sensible solution - not sarcasm. It's available at Homebase http://www.homebase.co.uk/en/homebaseuk/garden/plants-seeds-and-bulbs/turf-and-artificial-grass
Even using a weed suppressant membrane and mulching with gravel, bark, pebbles etc will not remove the need for 'gardening' as weed seeds will blow into the mulch and grow there.
Now do you see why you've been told to follow the instructions on the packet?
Weedkiller is not like medication.
Medication is to make something better but if you 'overdose' it can kill you.
Weedkiller is intended to kill weeds - that is what it is made to do and the instructions on the pack tell you how to achieve that - what would be the point of an overdose?
I think the people who tried to help you deserve an apology