Software ERP issue/ Cheating

We had entered in to a contract with an ERP (Private ltd co) in 2016 for customisation of software as per our needs. We are into Textile Manufacturing. Even after 3 years, they could not deliver and they convinced us that major of what is required is already there in their standard software. So we, without any choice left, went with their standard software. They told us that all the processes are linked. the software was supposed to start and get implemented on 1st April 2019, but their linking was so poor and there were so many errors, that it took almost 4 months to start. Till then we were running our old software paralelly, thereby increasing pressure on our employees and disturbance. After all our data entry which got running till october, 2019, we had a surpirse from them that stock valuation is not there at all. you have to manage. Over and above that, none of their reports are working and we are still taking all data from sql to excel and making our internal reports. Support from them is at level '0'. Infact in Jan'2020, they even stopped the software remotely due to the balance payment of 40000. All the data entry in new ERP was done by the directors as else staff was completely getting disturbed. There were 3 people leaving our office due to this. We now want to drag them to the court for disturbing our accounts. We are shifting back to our original software from 1-4-20. Please guide.