Lombard Bad Faith

I am claiming as a 3rd party and Lombard sent me settlement offer on 23 June, which I accepted and sent back the same day.

2 days later and they act in bad faith, which in my opinion is a breach of SAIA code of conduct.

Lombard do not want to fulfill the 1st legally binding offer and are trying to rescind the offer and have me take a lesser amount.

As they acted in bad faith how can I possibly trust the won't do the same thing with the 2nd offer.

I was told they would pay 1st offer in 5 days and today is day 5, still waiting for payment.

I have emailed Lombard twice and received no response.