Several times now I've received phone calls from numbers I don't recognize. When I answer, the other side claims that I called them (which I didn't). Most recently this happened yesterday. Call came in at 3:57 PM, which I didn't answer. Call came in at 4:36 PM from a different (but similar) number. When I answered, he said he was returning my call from about an hour earlier.
One of these calls also came in on 6/27 at 7:09 PM.
In all three cases, the first 6 digits were the same as each other, and the same as my phone number. Only the last four digits differ.
Is this a scam? Is this a glitch in Sprint's phone service?