Did you use Fable, set Opus 5.5 to xhigh, or use 'ultracode' / workflows? That's the only way this will happen.

In my experience a single 5 hour allowance in the 20eur Claude plan equals about $10 in Deepseek 4.1 Flash API usage. DS is a lot more token hungry and takes 3x-4x longer. The subscription is way cheaper, probably around $200/month worth of DS, just stick to Opus low and Sonnet for most tasks.