Am I being unreasonable and How long do funerals usually take to arrange? UK

So, my mother in law passed away in hospital on Friday 17th January, we’ve since been waiting for the doctor to sign the forms so we can go and register her death and get the death certificate we need to arrange the funeral. After a week went by we decided to ring up and was told that the doctor was on annual leave and would be back today, 28th January, bare in mind that whilst we’re waiting she’s being kept in the hospital mortuary not somewhere her family want her being kept. We’ve penciled in a date for the cremation but the funeral director can’t hold this for us until we have the death certificate. Today the hospital rang us and said that the doctor at the hospital is off sick and they don’t know when she’ll be back and we have to wait for her to get back to sort the forms. Now I went a bit off at this point saying how it wasn’t good enough, I asked if anyone else’s loved ones have been held there for 11 days or just her and they said just her as it’s got to be the specific doctor that has treated the patient. Am I out of order to be upset by this and having a few words with her on the phone? It just doesn’t seem like it’s good enough at all. Thank you!

TLDR: waiting on a doctor to release my mother in laws body, she’s been on annual leave now is off sick, am I wrong for being mad?