There do seem to be several reasonable justifications for aTriz to currently get out of the signature contract, and one of them is the post quantity question.  Another is the degree of red trust that you have received.  Another is the covenant of good faith and fair dealings and possible fraud in terms of whether there is any way that he could get what he thought he was getting out of the contract when there is a decent chance that you are misrepresenting on your end to such a high level that aTriz was mislead in terms of your ability to contract or to carry out the terms of the contract on your end so that he could get the benefits of the bargain.

So one thing is aTriz getting out of making further payments to you, and another thing is if he currently is entitled to a refund for the amount that he had already paid. 

Even in a scenario favorable to you if aTriz were to conclude that you were not clearly enough in breach on your end or that the contract is not otherwise invalid, in good faith, aTriz could decide to make any future payments into an escrow, because, in spite of your oral assertions, the odds of you reaching Legendary status within three years seem like a stretch into the implausible.  Furthermore, there could be some chance that your account becomes banned or suspended for extended periods of time, too, which seems to be an administrative discretionary matter, too under circumstances like this.

So perhaps a decent compromise would be for you to enter into some kind of voluntary bilateral dissolution of the contract with aTriz, in case aTriz would be interested in such a dissolution, and perhaps there would be some friendly terms that could involve your ability to keep some or all of the payment that aTriz already made to you?  Some kind of agreement or arrangement by you might at least save you from receiving some additional not yet administered red trust.