Get a hold of Ultra Tunes head office fax and send them details in writing. Use your time effectivly this weekend and write write without too much emotion or threats. Include things like what the mechanic said. Possibly ring them first thing Monday and get the name of the person at Customer Relations so that you can direct the fax to the right person. Unfortunatly you should still pay the bill but you also have to give them the opportunity to fix it though it seems the mechanic is at a loss anyway.
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