The funds that this user deposited and played with were withdrawn in full on 1 Apr. The funds in his current balance are affiliate commissions from his 1 referral, who was determined to be an abusive player.

The OP only has 1 referral and it is extremely likely that the referral is either himself or someone working together with him.

Regardless, our affiliate program terms state:
https://support.betcoin.ag/hc/en-us/articles/24598735637147-Betcoin-ag-Affiliate-Program-Terms-and-Conditions
We reserve the right to terminate an affiliate account at any time if there has been suspected abuse by the affiliate or its players, with regard to our anti-fraud policy.