Unfair refusal to process our medical claim

Affinity Health is by far the worst medical insurance I have had to deal with. I put my sister on this insurance in 2016 when she was 8 years. On the 7th of April 2018 she had an accident while swimming and had to be rushed to casualty. When we called the medical insurance preauthorization number, we could not get through and eventually the hospital insisted that we pay cash for her medical treatment and claim from the medical insurance. We did exactly that and I submitted all the claims forms and statements we received from the hospital. It's been over a month now and I have been calling Affinity almost twice every week to follow up on the claim, but for some reason I would be told different stories every other time I call... I still provided all the information, with the help from the hospital, but have unfortunately not been able to get any proper feedback or assistance from this company. This is not the first time that this has happened. The last time it happened was in 2017 March, again when my sister had to be rushed to hospital, we could not get through to authorization on the number they keep providing as their pre-authorization number. Again when we wanted to claim for the bill and after submitting all the forms and statements from the hospital, they still refused to pay with no valid reason. I have ended up deciding to cancel this medical insurance as we have found it to be so useless but yet always claiming premiums every month.