Constant error messages

System worked extremely well for about 3-4 years. However, over the past year, we've had constant problems with error messages: "Entry sensor not responding" or it claims a door or window is open when there isn't. We've changed out sensors, gone through resets several times with a customer rep over the phone. The last reset (removing ALL batteries from all sensors and base station with rep on the phone) was just a couple of weeks ago, and still, I've received 12 error messages just in the past week. It's too frustrating and time-consuming. Ready to throw this one out and try a new system. Wondering if anyone else has had this issue and if it was successfully resolved?