One-off job

 am looking for someone in Lanzarote who speaks both English and
Spanish to run an errand for me and earn 100Euros or possibly more.
Here's the story. I am an old man passing through the Canary Islands
on my sailing boat. Three days ago, my brand new mobile phone was
stolen when I was in the Dino Supermarket in Arrecife (I must have put
it down and someone else picked it up).
I bought a local SIM card, put it in an old phone and tracked the new
one to an address in Arrecife. I went to both the local and national
police stations but they simply referred me to each other. No-one was
remotely helpful.
I don't see the point in going to the address myself because I don't
speak Spanish (the "Learn Spanish" app I was using is on the lost
phone). Also, I suspect this might be a good way to get mugged.
What I need is a local who speaks good English who would go to this
address, ask around and offer to buy the phone – after all, it is
password protected and now locked remotely so it is no good to anyone
else.
This middle-man would negotiate a price, buy the phone for as little
as possible and then meet me in Playa Blanca sell it on to me for
200Euros.
Can anyone suggest someone who might be willing to help?