5mnths after pre auth procedure claim not resolved

Five months after a hospital procedure, which was pre authorised, a claim still not fully paid. Have phoned call centre often and recently every day to try and resolve this, and I have had to pay for these long calls from my cellphone. I finally have an unsatisfactory response today with a massive shortfall on the claim. I cannot claim from gap cover as Discovery took so long. I have been a member for 14years, that this is how they handle matters. Seriously looking to change my Medical cover now. Disgusted with their service.