Amplifier

I took an amplifier on account.It was not the only thing I had taken but with other things I'm fine with I'm not having any problems.Then there is an amplifier that stopped working I had to return it in store after 2 months of having it.It's been 3 months now if not 4 since the amplifier has been by the store.I tried going to check their progress regarding my issue and nothing is being done at all.The store employees just keep on telling me stories.I have been paying every month