Their legally binding deal said that if as July 18th the acquisition wasn't completed, Microsoft had to pay another compensation to ABK, this time of $3B and that the deal was over. Prior to this, there were other previous milestones with their related penalty compensations that MS has already payed because they weren't able to close the acquisition before these other milestones. So yes, make sure MS will pay them these extra $3B too.
After having missed the last milestone, they signed another deal to extend the deal until October to see if they can do something with the CMA and FTC to get the acquisition approved. Which I assume will also have another compensation clause where MS will have to pay a handful billions more if don't complete