https://console.worldoftanks.com/en/news/trade-in-chisel
Seems with update 4.11 will be the next Mercenary Tank contract available.
And you could achieve the requirements for stages easier if you have the listed Premium Tanks?
Should this give the Trade In programm a push as it is not working as expected?
Does somebody have more Details about the Chisel? Looks like a Medium Tank.