No red meat does not stay in your body for 7 years as that would not be possible.
Your body will digest the red meat within 72 hours at most as long as your digestive system is working properly.
Some meats just take longer than others to digest but the meat should always be digested at least in 72 hours and if not then you're having digestion issues.
If you're having digestion issues then you should see your doctor.
7 years would be way too long for red meat or any other meat to stay in your body and it would really rot out in your stomach and make you sick if it did that.