This comes up a lot. Great question! Sometimes, things happen in life. Realtors work with many different clients and try their best every day to provide excellent customer service, but they are people too and often face personal events that prevent them from doing their job (temporarily of course). There is no excuse that you were not taken care of for 3 weeks time,however did you let him/her know that this upset you? Common knowledge says that this Realtor should have known that you were upset, but if they forgot about you and their friend never reached out to you that should at least be expressed to him/her so that they don't entrust in that person to assist another client down the road. I would call them and let them know that it really upset you and see what they have to say. You will know if it is time to move on or not and this way, you will feel better knowing you tried your best to resolve an issue with someone who truly helped you in the past and can gain clarification as to what went on before. Best of luck!