Pay someone to fix a mediocre pair of $40 headphones? Not by a long shot unless they'll do it for $10 or less. And even then that's 1/4 the cost to replace them.
Take them apart yourself, see if there is just a wire that has come loose and if so reattach it. If the solution is either A) not obvious, B) not repairable or C) cost prohibitive, just buy a new pair.