alternator itself repaired (instead of 900€ – only 30€ !!!!!!!!!)

Would like to report something. My S80 2,9l, EZ 2000, 184 tkm., at once wont start any more, reported “voltage too low”, ADAC camem after 40 min., – battery lesson – Limo gives no current – onboard voltage only 11V – drive too dangerous (from 10V off engine) – towed. Volvo says – soda broken and battery almost dead – soda new for 900€ plus battery. I ask – only the controller is broken? Volvo – can be, but if already, then better replace whole soda, who knows how the shaft outsie ht, for new controller 500€. No, not with me. Controllers increased for 30€, approx. 2pcs. work in the garage – and now the on-board voltage 14V. Since 2 tkm. is driven, battery still lives, the controller also. Oh yes, Volvo has collected for diagnosis 50€ (I could save that). Conclusion: who dares not – who pays.