Extended warrenty

I have been waiting over 3 weeks for the repairman to call me and tell me the part is in for my range ! I call him and get the run around, I'am not home to check and see if the part has come in !  When he found out the part he needed he said oh, I know the part you need, well if it was that common why does it take so long to get the part !  Very upset, will not be renewing my extended warrenty ! Whirlpool, you had better be checking out these people who take the problem and then ho they call to service the person who has the problem !  Customer service is not what it use to be !