Upgrade center cant upgrade or work the new system

I am trying for the last two weeks to do an upgrade but no one gets back to me. I phoned yesterday again and was put through from one department to another and I still cant upgrade after about 45 minutes. Do you still want my business as I had my contract since 2001. Here is my ref nr's Z2UCED, 2091X0, U9EKQC. Today I was told to phone *** as I was migrated to the new system that no one cane work from December last year. I phoned and was once again put thru several departments just to hear I must do my upgrade in store. The reason I make use of the online system is that I am physically disabled and I struggle to walk due to motor neuron disease. The store where I live has no customer service at all. You do an upgrade then the tell you just to put in your sim. when discovering that you need the smaller sim they just say the upgrade is complete and you must by the sim, that happened to my father. they also never gave him his top dog voucher some service hey. I hope you cane be of assistance.