Hydraulic Tensioner

[susanavilon]

I had the timing belt changed 3 weeks ago. On the way to work last tuesday. I heard this clanking kind of noise and took it back to the garage. They are now saying that I need the tensioner replaced. I would like to know if it is possible for the garage to have perhaps over tightend the belt or something causing the hydraulic tensioner to break. Is that possible or am I just hoping not to have to pay about another $600 + repair bill? Things were fine until I proactively decided to have the belt replaced.