Here's what I think is going on 
So he didn't seem to be surprised when she woke up. So he got medicon from her but couldn't pay for it, he bought it from a really dangerous guy 
he can't use any other phones because they could track it and he can't but anything cause they could track that as well. He won't tell Eru cause he knows that if the guy tried to hurt her to getinformation she  wouldn't tell him anything and he would just continues to hurt her