Hedge Trimmers

I purchased a Husqvarna Hedge Trimmer 122HD60 in March of 2015. The first time I went to use it, I ran it for about 1 hour and then it wouldn't start. I took it to a local authorized Husqvarna repair dealer and they said that they found a piece of dirt in the carburetor. It cost me approximately $80. I had not used it again until this year. When I got it ready to use it would start right up but after a couple of minutes it would not run. It would start and idle but as soon as the throttle was opened it would quit. I took it back to the local Husqvarna repair and they called me this morning to let me know that the muffler was totally plugged up and that was the problem. I had thought it was something to do with the high and low speed jets in the carburetor which are completely adjustable but only by an authorized dealer. With less than two hours of use I am faced with spending a minimum of $170 dollars to get it to run after spending $310 to purchase the Hedge Trimmer.
If this is the type of service a person can expect from a Husqvarna product. I'm certain I would never buy anymore of their products. I could understand the possibility of dirt getting into the carburetor but I don't understand how a muffler can get plugged up to a point of not allowing the engine to run after less than two hours of use. There has never been any mention of the fact this might be covered under a gauarntee. Any help you can provide would be appreciated.