I am not sure what your experience with the agents you have called has been in your area. I am also unsure as to what you are requesting from them that would cause them not to respond to you. However, your other question concerrns whether or not a seller should pay any commissions to the agents. I do believe that Realtors work hard on behalf of their seller clients. This means not only responding to yours and other calls that come in, but also marketing the properties in order to get you and other buyers to call on the property, to schedule the showings with other agents who wish to see the homes they have listed, making sure that the seller is aware of all the things that need to be done in order to get it sold, to assist the seller in reviewing any and all offers that come in and advising them on how to respond to the offers that come in, advising the sellers on any inspection addendums, advising & assisting the sellers through everything that can happen from the time the home is listed for sale until the time that the home goes under contract and finally, to the time that the home actually closes. The seller agrees to a commission that is negotiated between the listing broker & the seller, and that commission is then split between the listing broker & the buyer's broker. When a Realtor is representing a buyer, again, there is much more that goes into the process besides finding homes listed for sale in Multiple Listing Service and showing the home to the buyer. The buyer's agent will not only do these things, but will assist you in preparing your offer and explain the contract paperwork so that you understand exactly what you are committing yourself to, will recommend inspectors for your whole home inspection so that you will be able to have an inspector that you can rely upon to do a thorough and quality inspection (rather than taking a chance on a name that you found in the yellow pages or internet), will work with you on how to structure your offer, will be there to assist with the negotiation with the seller, will run a Market Analysis for you so that you can make sure you are not overpaying for the home, and will be there for you from the time you begin to work together until the closing, and even after that! I think that the Realtors who are out there working hard for their buyers and sellers do a great service for them, and many times buyers and sellers are sometimes unaware of the glitches that can come up as the agents are there to help smooth over those glitches so that you will end up having a smoother closing. We can't control everything, and sometimes things may not go as smoothly as we would like, but I think that the commission that is earned by the Realtor is well worth what is paid. Of course, with the internet, it is possible that you could do all these things on your own, but as a buyer, you are not guaranteed that you would get a break on the price simply because you are using the listing agent or you are representing yourself.
I know this is a very long answer to your short question, but I hope that this explains to you some of the things that we Realtors do for our clients. And also remember, we do not get paid until your transaction is closed AND recorded! Good luck to you with your purchase!