It may not feel like it at the moment, OP, but you are doing so well. 
When a loved one's death is so very recent, functioning at all can seem more like battling uphill in a fog. So keep on keeping on, at the very slowest pace circumstances allow.
Exhaustion/ anxiety/ stress of trying to hold things together is debilitating; it's ironic that it's precisely within those first bewildering days that so many practicalities have to be dealt with.
Something I found invaluable was appointing 1 of my most trustworthy and reliable friends to act as a 2nd tier 'buffer'.
For when we, the immediate family, just couldn't cope with repeating the same upsetting details to yet more people, or returning yet another urgent phone call etc.
Prioritise talking directly to anyone essential, or who will genuinely prove comforting and sensitive to you, but otherwise delegate to the Buffer Friend(s) the making of (polite but very brief/ factual) calls on your behalf (even texts/ emails, if and when appropriate)... frankly, anything which might save you (your Mum/ brother) a 3 minute 'quick call' developing into an exhausting half hour detailed account to anyone more persistent and demanding.
Sorry Vodaphone caused you hassle. Last thing you bloody need. 
x