Claims not being paid

I have been struggling every single time to get my ostomy claims paid. Every claim I have to explain several times how the scheme tariff should be app**** and that there is an ICD10 and Nappi code and please stop using the product code and then tell me it is invalid. I've submitted a claim for treatment date 29 December 2017, that is now being not allowed reason being submitted to late. This claim I have submitted several times, the following were issues: Procedure code and ICD 10 code...it was on the invoice and for the first time in this claim it was an issue that the ICD code is not in the same line on the invoice as the product description...I still have to draw arrows to assist Discovery to find the code next to the words "Nappi" and "ICD10". The application of the scheme tariff was once again incorrectly app**** and no feedback after several calls, where I was promised that they shall contact me to inform me on the progress. The second last call on 30 April I was promised the world, feedback and that it should now be sorted. Treatment date 14 November 2017 all the same mistakes were made but was eventually sorted. The company Hollister told me that they refuse to claim from Discovery and that I should pay and claim myself...I see their point!! After 5 years I still have to phone in after every single Hollister claim to explain the claim and correct errors being made. Life is to short to spent that amount of time on a phone and it is cheaper to just pay the expense myself. Claiming for ostomy products from Discovery is more of a challenge than being paraplegic!