It’s a fairly common problem. You magickal activity create light and ripples in the astral that are very interesting, and attract attention. Some attention is just curiosity, and some if from those with agendas, and some from hungry entities that feed on that kind of energy and are looking for an easy lunch.
More advanced entities can insert themselves into the connection, usurp it, and claim to be what they are not in order to get tour attention and energy. People often figure that out when they start acting out of character, and/or simply can’t deliver on the promises, or start making weird demands. They’ll also schmooze you and tell you grandiose bullshit, like you’re suddenly a prince of hell or some such nonsense to appeal to your ego and keep it going. They may switch between buttering you up and threatening you, it gets very abusive and gaslighty the longer it goes on.
Assholes are everywhere: as above so below; as within so without, (Hermetic axiom) so, it’s worth knowing how to recognise and avoid them both on Earth and in the spiritual realms 
Raise your vibrations to cut out 90 percent of them instantly.
We have some discussions on impostors here, and a few are collected here: scroll down in the first one for a good impostor tutorial…
and once you know you have a freeloader you want to get rid of, here’s how…
Commonly, first you make sure your senses are developed enough to get communication happening, then you can ask it to show you it’s sigil in your mind’s eye. There’s a belief that seems to work, that an impostor will show you it’s own sigil and can’t show you any one else’s. I don’t know why this works: they lie about everything else, but there seems to be a rule, you can lie with language, but not with direct telepathic images.