LA music Shady, unprofessional, Lies, Cons, deceit, over priced, Mississauga, Ontario

I am a Musician of about 20 years, own many guitars and have a JMC 2000 Marshall head. Recently i went into A Guitar shop located in Port Credit Ontario Called LA Music to help me with problems that i was having with my Marshall amp.
 when i came in and explained my problem the FIRST time i let them know that there was a volume problem, and that the amp was cutting in and out. I also ask them to please give me a call before they proceed with any repairs so that i know what kind of price i will be looking at.
that same day they called me back with a diagnosis and a quote on repairs. said it was my 4 pre amp tubes that were weak and needed to be replaced and it will cost me $180 for parts and labor. i agreed to it and let it happen.
they called me back at the end of the day saying it was ready for pick up so i came in and they tried to tell me that the price quote was wrong and that it took extra time to repair so it was going to be $220. i am not new, i know what it takes to change a couple of tubes... i argued with them saying you quoted me one price i wont pay any more. i ended up paying what they quoted me.

the next day i was in rehearsal with my band, and not even through one song the amp cuts out and the same problem persists.
i called the store the next morning upset saying that the problem wasn't fixed, they asked me to bring it in to look at it. they ended up taking it in, at which point finding a whole different problem to diagnose, saying it is my main power transformer. i ask how much to repair and they quote me $380 for parts and labor. with that money i could have bought a used amp or a smaller brand new one. plus my amp was now on there bench in pieces

at this point my amp is being held for ransom and i will not be able to get it back unless i pay the fee. in total i am out of pocket $560 because of there faulty diagnosis of the problem and they were in no way willing to help me out will the cost due to there negligence. keep in mind i have never payed this much money to repair my car let alone my music gear.

later i posted my anger with this store on my Facebook page to the many friends that i have in the Toronto music scene only to find out that others have been taken for similar rides as mine by the same guitar Store... STAY AWAY!!!... rip off!! do not deal with LA Music... shady people, shotty work, unprofessional and rude.