Tata Consultancy Services — Not ready to make onboarding after issuing offer letter letter and DOJ

I got offer letter and DOJ. And I got several remainder mails to join to on the day they provided. And they didn't share any mail regarding joining and when I ask them the reason that background verification have some issues ( related to salary slip) and I submitted the documents and ready to provide contact means of my ex-company HR or director with their consent. Issue here is they didn't inform me the issue even on the day of my join. They simply cut the communication. And I resigned from my previous company to join TCS. I got the information only when I asked them the reason. After I give them the documents they didn't give the update and even HR also not replying. This is very unbecoming of company like TCS. I respect the process and ready to make the issue if they informed me earlier. Now I'm jobless because of them. The background team was called Matrix they also very rude while asking me the details.
I have proof that they provided me all the joining commitments and didn't inform me anything regarding issue.