Flooding underneath my property.

Property flooded underneath back to front from Yorkshire Water unmapped unmaintained drainage to the front of our property.The lateral drain which takes surface water for both properties and pumping station located 2 metres from our front door were so badly blocked it resulted in the adjacent main road being dug up 45 metres down the road .They offered no help told us to buy a pump to remove the water ,how can we pump water out if the drainage is blocked so this water as been sat since July damp spreading throughout our property .And private drainage report shows not repaired and will continue to flood .Offered £50 for any inconvenience £80 for pump and £250 towards increase in premiums not insured as damage is prior to purchase.None of this drainage was on searches when we purchased property.And the water was only found when renovating.Yorkshire water say no liability for sewer flooding .Insurance says this is not escape of water but damage to drains.We are left facing Thousands pounds in damages but are still left paying our bill which includes Surface water removal and Highway drainage .Absolutely disgusting how they can charge for services they haven’t provided then refuse to pay compensation for this negligence.