Top AM Firm Ghosted me After Signing FT Offer Contract (Summer Associate - FT Hire)

Hey everyone! I was hoping to get you input on a situation I have with the firm I interned in 2021. 

In summer 2021, I worked with an asset management firm (AUM over $2 trillion) as a summer associate and I was able to secure a FT offer with them. I ended up accepting the offer, but my graduation date was unfortunately postponed a semester due to a class I had to retake. Once I got word of this I ended up contacting HR and they said they'd get back to me within a few months, but they ensured that it shouldn't be a problem. They basically implied that a January 2023 start date wouldn't be an issue.

At first I was worried about the offer being rescinded, but after reviewing the contracts I noticed that it didn't specify a graduation date/start date or anything related. So I kind of brushed it off and assumed it was okay. 

Long story short, months passed by and I kept following up with them and they NEVER got back to me. I just graduated December and I'm still literally in limbo with them. I spoke to professors/family/friends/colleagues and everyone is telling me to sue because the contract is legally binding. I'd consider doing it, but the thing is that I don't necessarily want to burn my bridges or have lawsuit impact my ability to land a job in finance.

How would you guys proceed with this? Any bit of advice is appreciated!