In reply to peter:
Did you check #1 that I suggested? Did you start your sequence in your test?
Check again the line:
seq.start(env.mem_agnt.sequencer);
Please make sure you have the line above in your test, the body method is executed once you start the sequence correctly.
One more thing, as I mentioned in #2, dont use raise/drop objection in run_phase of driver where you have forever loop. I dont think your test will finish with your implementation.
The objection should be raised/dropped in your test only where you start the sequence.