Halifax Pet Insurance

I have put in several continuation claim to halifax pet insurance over the last 6 weeks which add up to £1000. I have received back so far £300 which i had to chase up daily as they kept saying they hadnt received any info from vet even though the vets assured me they had sent it.

Now i am still trying to get the rest of the money thats owed to me and they are saying they not received any correspondence and keep mixing the claims up.

Any advice on what to do, has anyone else had problems getting their money back.