Where to fix speakers

I think its quite weird what have just happened.
I was watching a movie on DTS mode and all of a sudden my center speaker and left front speaker just went silent.
I thought there was something wrong with the output but when i put my right front speaker into the left output, it does produce sounds.
Then i thought there was something wrong with the cables so i swap a temp cables just to try out the center speaker and left front speaker but they no longer work.

Any idea what could have happened? My brand of speakers are Fidek.
If so, any recommended place where i could fix it?

Thanks

Have you tried in Dolby Digital, ProLogic and Stereo Modes and see if the problem still persisted?

Yea, i have tried all of them.
The weird thing is that the right front speakers are working and not the left ones.

Did you try swapping the left speakers to the right to confirm it's the speakers?
Don't connect the right speakers to the left as it could be the left channel from the amp that could be giving problems - you may end up with another busted speaker if the left channel is the problem.

I have swapped the left speakers to the right channel output and it is not producing any sound either.
So do you think i got a busted speakers plus a defected speaker output at my amp?