Every call I have received per my Google ad (I.e. when the phone rings it says "this call has been generated by your Google ad") has been spam. One was a lady asking for my price on pie tins, I clearly don't sell these and she was mad I wasn't a wholesaler... A child was pranking me asking me if my fridge was running..... And a guy called at 7 am claiming my phone number had called him and he was returning my call... When that wasn't the case. Am I being charged for these because if so I may need to cancel?
Hope you are well.
Unfortunately, you're going to be consistently surprised at how ridiculous some people can be online. If your targeting is correct, there's not much you can do about people who you're targeting actually calling.
I'd encourage you to dive a little deeper and look at the audiences, locations and keywords that you're targeting and make sure that you're doing everything you can to wed out these types of calls. The majority of my work on AdWords accounts is actually weeding out irrelevant traffic. Unfortunately, you have to get the bad traffic/calls first to know what to weed out and to know what targeting works and what leads to stupid calls.
As for the guy who said he was returning your call, you wouldn't have been charged for this. It's likely he saw this number somewhere and it's been recycled (there's only so many phone numbers) by Google to your account.
If you want to share your targeting, I'd be happy to offer some pointers on how you might want to tighten it up a little bit. Alternatively, you might want to stick with text ads for a bit until you get a feel for the audience you're targeting.