Expecting customer to rectify mistakes

I sent Oneplan a claim and on the email addressed, said 'pay to member''. I also sent them proof where payment was made by myself, they then requested a full invoice from service provider, which I provided. The account then gets paid to the service provider. Instead of the claims department rectifying this mistake, I was told to sort it out with the service provider. this is completely unacceptable, seems there is no recourse for them not doing their jobs properly and this just causes more administration and follow-up by the client. When I called the claims department I was told this is not the first time its happened.