Easy answer: be patient! The Balancer team has no control over when they airdrop, as other teams are responsible for giving out their token rewards. So far, airdrops came in from Wednesday to Thursday for the previous week.
Please check your address using https://polygonscan.com/ for any incoming ERC-20 txn's or internal transactions that would indicate you have received rewards.
To check the amount of rewards you are supposed to get, please see this answer in our Polygon FAQ: