EE mobile phone insurance question

maquis

My brother by accident dropped his phone in the harbour and it was destroyed;

On Friday EE said that they’d cover it but now are saying they won’t,

for some stupid reason about not being insured for water damage when it had damage cover and the guy in the shop didn’t tell him about the different insurances, damage or full and since it doesn’t give a definition of “damage” ex: by being stood on, run over by a herd of drunk Rhino or water damage shouldn’t that mean its covered and the idiot in the shop also said to my brother that if he bought a new phone that the insurance would cover it?
And isn’t that bit about getting a new phone a loada bull crap?
Does anyone have knowledge that could help us in this case?