What is entailed for someone who intentionally broke their fast in Ramadan—whether by eating or by masturbating—for ten years, at a rate of 15 days in each Ramadan? And how can the expiation for these 150 days be fulfilled, taking into consideration the noble hadith "Allah’s debt is more worthy of being paid" and the accumulated debts? And what if death overtakes him before he can make up for them?

You must repent to Allah for intentionally breaking your fast in Ramadan (definition). If one intentionally breaks their fast without intercourse, only making up the missed days (qada') is required, not expiation (kaffarah (definition)). Masturbation in Ramadan is forbidden, and it does not invalidate the fast unless semen is discharged. Only qada' is required if the fast is invalidated by it. If qada' is delayed until the next Ramadan without a valid excuse, an expiation for delaying the qada' is required, and it does not multiply with the number of years. Feeding the poor is not a substitute for qada' except in cases of chronic illness or old age that prevents one from fasting.