cannot see picteres until they are approved but from your description its unclear what they have done and exactly what the description on the cable marked "pull on this for new drop" means - so am guessing a bit - you dont say how close the 2 ends come together but if they are close then get one of these and join them
https://www.ebay.co.uk/itm/183829316019
if they are a distance apart then you will need to try a bit of 'make it up as you go' - so
the above fitting or 2 and
https://www.ebay.co.uk/itm/282077526694
assuming the cable marked to the drop is good then that should work
those are just examples from ebay - B & Q may sell them - they certainly sell the 1st one
