Is this considered gaslighting?

Sometimes it could be the service or something going on with one's phone. If you have no service you won't always know that someone has called. Aside from that... Sometimes someone can call you and it not go through for a number of reasons. I don't think gaslighting is the term for this particular situation. I've been through this before. Most of the time I figured they were lying. I would just at this point say look if you don't want to talk or have better things to do, let me know. There's no reason to lie especially if you're just friends.