Flight Crew Commercial
ATC Issue All Types; Conflict Airborne Conflict
Flight Crew Took Evasive Action
On arrival into IAH we were given an altitude to descend to on the arrival. After arriving at the assigned altitude ATC called out a traffic advisory at between our 10 to 12 o'clock and 500 ft above us. We got a TCAS TA and were still unable to locate the 172. Then we were given a TCAS RA to climb which confused myself and the Captain because the traffic was 500 ft above us. This caused a moment of delay and then I responded to the RA by disconnecting the autopilot and climbing. We then got and RA to descend which I then did and then another to climb. I could see the traffic on the MFD was still to our 11 o'clock position so I made a climbing turn to the right to get out of the situation. Once I did that the RA went away and ATC asked us about our altitude deviation. The Captain replied that we had responded to an RA and we returned to our previous course and altitude. The separation provided by ATC was inadequate. We were unable to acquire visual contact with the 172.
CRJ-700 crew received conflicting commands during an RA. This followed a traffic advisory from ATC. Following a second RA vertical command reversal; crew turned away from traffic displayed on their MFD to resolve the conflict.