I recently bought a house and the seller had a Rad...

I recently bought a house and the seller had a Radon Mitigation System installed by Just Fix It. Once I moved in, it was hard to sleep in any of the downstairs bedrooms because the system shakes the whole lower floor and makes a nasty deep bass sound. I reached out to Just Fix It and they sent a guy out to look at it.

He told me that they needed to install a rubber fitting and they would have to come back with the right parts/tools. That was over 4 weeks ago.

They have completely stopped responding to my calls and texts. I wrote an email hoping they would respond to that, but I'm not getting my hopes up.

Is this the typical business ethic of this company? I'm in the process of getting another contractor to finish the work they have already been paid to do.