House insurance claim appropriate?

SRT

Sorry for lengthy post but it could be longer.
July 29th 2016. I discovered my tiled (limestone) kitchen floor appeared damp under cupboard units which are not tiled, just the older concrete on which new tiles and electric heating mat are laid in main walk areas. I know that hot and cold freshwater supply pipes run under this concrete across the floor space to a sink and dish/clothes washers. Where the pipes enter and emerge there is green verde de grise which seems to indicate a leak.Contacted insurers who agreed this was covered "Sainsbury Premier" and advised I contact Dyno plumb. Their visit revealed a pressure drop and evidence of a leak.
Sainsbury were notified who then instructed UKDN to visit for further trace. They called twice and agree leak is evident.
I am trying to get a response from Sainsbury who seem incapable of replying as to what I should do next. I thought they should have some agency who they would instruct to resolve the leak either by re-routing pipework (favoured) or lifting floor (worst case scenario):(
Does anyone have any advice on what I should do and am I right in thinking this is an insurance company liability?

Furts

Your cover will be as listed in your policy.

I wonder if the insurers might bounce this back to you. Hot and cold water pipes should not be in concrete floors. If they are in a screed then they should be sleeved/insulated/protected and allowed to move. It sounds like you may not have this.

How old are the leaking pipes?

SRT

Sorry for not getting back sooner but some things have progressed but not much. The pipes have been in the present location for over 30 years back when I moved in. They were probably installed by the previous owner but I cant say for sure and almost certainly 10 or 15 years earlier. My insurance company have now sent several people round to view etc and agree that the leak is due to the corrosion of copper and concrete/cement. The cover is listed and agreed btw but its taken forever for insurance to get things adressed. They have now told me to get the original kitchen fitters involved as the removal of units is required and re-routing of pipework. I have just spoken with kitchen fitters and they are happy to help but are amazed that I am having to do all the running around contacting people. Ive sent insurance company the details and now await further response.