So frustrated

My husband died. His name was on the account. I have been trying to get our landline transferred to another company, Straight Talk. I have sent in the death certificate, I have called many, many times, visited the local store., nothing gets taken care of. Either they tell me that my husband must be with me to make changes (it’s painful to keep having to tell them he’s dead, only for them to seem to forget), or they tell me that that my daughter can call in because she’s authorized (but when I made her call in, they said she couldnt make changes) or yesterdays agent wouldn’t listen to me and tried to move my cell phone number over without my permission and now there’s some random persons cell number on my husbands account, unsure where that number came from), or the store employees who signed me up for an account but didn’t do anything with my husbands so are you all expecting double payment? Why can’t I get my landline number transferred to straight talk? Why is this so hard? I’m a grieving widow and this is so stressful.