Chat Programmer Needed to Fix Broken Features

My partner and I have had some difficulties in the past with our hired programmmer. We first purchased a chat software program from Rapids Chat only to discover that though their website details a list of features included in the software, it did not mean that all those features actually worked. After payment was issued and the software received, we discovered that nearly ALL of the features listed as included in the software were broken. Rapids then required additional costs to fix what was broken with the software upon purchase. At this time, my partner and I did not feel it was professional to sell us a broken version of the software and then demand additional costs to fix it, and thus we went elsewhere. This time we hired a programmer to design us a custom software. We provided them with a list of features our chat software would require, and allowed our programmer to choose his price. Three months later, after discovering all of the features we requested were broken, our programmer decided it was not worth the payment they established to fix the software. They in turn offered us a newer version of the software for additional costs. My partner and I then decided that this programmer was hired to design us a CUSTOM SOFTWARE and that we were not intitled to pay additional costs for the version of our own custom software that had all the bugs corrected. We explained this to our programmer and reminded them of the contract in which they agreed to provide us with a working software with the required features for the payment they set and had received. That programmer has decided to announce our contract as VOID. If we were not interested in paying additional costs to fix what should not have been sold to us broken in the first place, then it wasn't worth their effort. So now we have TWO running software programs both with broken features. We are looking to hire a programmer with the knowledge and ability to fix the coding of these features so they work as they were intended to work.