>>3668997>>3669000>>3669003fucked up frame counter on minolta X series is a rather common problem. a bad hit in that corner can easily knock a piece out of place and mess it up.
it can be fixed, but it's tedious. you have to take off the top cover and advance lever and reset the counter mechanism following the service manual, page 33 and 34 (you can find it on google).
up to you if you wanna send it back. if you paid full crazy stupid high price people are asking for X700s nowadays and seller didn't disclose that issue, then at least try getting a partial refund to "fix it", even if you're using it as is.