Hi Jilly1949,
Try resolving the matters with the agent. Express your concerns and point out things that you are not happy about. Tell them what you intend to do and what you want to happen. Communication and resolving between the parties is the best solution. Going to Solicitors and Court can be stressful, costly - money wise and time wise.
There are number of reasons why the agent has not keep you informed:
1.) Agent was probably told by the purchasers to wait until they have a definite answers in relation to buying your home. Therefore, agent is not sure of what to tell you.
2.) Agent could be looking at different options for you. Maybe looking for another buyer. Remember that the agent is working for you not against you.
You shouldn't be concerned if the sale of your house is not definite with the current purchaser, maybe your house doesn't want you to move. Sometimes the house choose the buyer not the buyer choose the house. Maybe the next buyer will pay the higher price.
If you are still not happy with the current agent, you can always change agency in your area. Or just write to Real Estate Association and express your concern. Look for what association they are members of.
Always remember that things happen for a reason. Hope that my advise has been a help to you. Take care and have a great day.