Refusal to settle insurance claim

I had an electrical fault on the DB board on a Saturday evening. There was a loud bang we saw fire on the DB board. I went onto the Ekurhuleni website to check who can assist at that time and got a lady who said she will send an electrician to come check. So the electrician came and replaced some wires and switches and all came to R11k which I had to pay. I then logged a claim with Nedbank and 2 weeks later they sent a supposed 'own' assessor who told them the job done was not as per the claim I sent. In short they said they will not honor my claim. Their call made due to what the initial repair man told them and what the assessor also told them. Basically the quotation I paid was far too high for the replaced items and the job was also not according to their or should I say the contract I signed with them. I asked them to then send their electrician to come and fix, they refused. Basically I have insurance which cannot help me at all. If they say I breeched the contract surely there must be a higher excess I pay, but to blatantly refuse to assist me as a paying client leaves me with no choice but to move my bond to a bank that will treat me with dignity and value for my insurance contribution. So good bye Nedbank, after 15 yrs with you am mad at how you handled my claim.