GC backed out of Verbal/LOI

I’m a sub contractor and had a scope review meeting with a GC. After meeting we shook hands on the scope of work and they stated they were happy to start working with us. A week later my superintendent shows up on site to look at our scope in field with the project manager. Months go by and we still have yet to receive sub contract. They did send us a scope to initial off on and we did and sent back. I followed up today and they stated they decided to go with another sub on the project. Although we never had contract in hand but still had a verbal and out half a day reviewing our scope in field I feel as if I failed not keeping up with this. I get lost in a lot of estimates 15-20 a month 4-5 million. I’m wondering if this is something common GC’s do or how often this has happened to other subs. I contacted the GC and they stated they tried to reach us several times. I know 1,000% that was not the case. They had my contact info my president contact info and superintendent contact info. Not 1 email not 1 phone call from them.