1st; What is your DMA and actual zip code?
2nd; Sometime its not just YOUR local affiliate, but another one close by and they do not base theses on digital signla, but the old analog signal method; as far as I have read it.
3rd; if the affiliates deny you, and your zip is listed as served, then there is nothing your DBS provider can do, as they only enforce (by law) what zip code database DMA info they are provided.
4th; If you feel your affiliates are wrong in your predicted signal, then you can request a signal test to aide your cause. If you are correct, and the test proves you can't get any acceptable signals, then it is free and you should be able to get your waivers. If you are wrong, then likely you will be paying for the test and your waivers will remain denied.