@Beth24, I'm sorry to hear that and I think maybe you write a formal complaint to the manager and if the care home is part of a group to the general manager as well. I was the one to raise the subject of DNR with mum's care home at a care plan review. She was at the time a long way off needing one, but I was aware one wasn't in place and I didn't want her put to un-necessary distress if she did become seriously ill. The care home manager agreed with me, and shortly afterwards I had a very sensitively handled phone conversation with the home's GP and one was put in place. I think it helped that we weren't in the middle of a crisis at the time. I haven't seen mum since March but before then she was becoming more frail with every visit. However apart from her dementia she has few health problems and none of them are serious, so I can imagine it will still be a while before I'll be faced with the reality of what I've agreed to.
As to the phone call. That sounds like an excuse. They needed to get in contact with you and if they couldn't get you on your landline should have immediately tried your mobile. Is it worth telling them you no longer have a landline and just to use your mobile?
Hope you get an apology and are kept better informed from now on.