The biggest issues are almost always unmet expectations.
What did you agree to?
What did they agree to?
I would define where they are failing to perform, asking for a meeting with the Realtor, if that fails, with the broker.
In most cases (but not all) the seller thinks their listing is worth more that it really is. It is a shame that some REaltors are unable to communicate in a way that the sellers undertand the dynamics.
A listing has a short shelf life. 10-12 showings in 2 weeks should equal an offer. if not, lower the price.
If there are more complex issues (communication, not performing as promised) then address those. Realtors do not have any control of the market. If your home is over-priced, what you paid, how much you owe, how much you need to net...we have no control over that.