Is it permissible to pay the expiation only without fasting, or is it obligatory to make up the accumulated days of fasting that were delayed for years, in addition to paying their expiation?

What we understand is that you made up for the missed days of Ramadan after the second Ramadan, but you did not pay the expiation for delaying (the make-up) along with making up the fast. Then you made up the fast again. Making up the fast again is unnecessary. It is sufficient for you to pay the expiation for each day of the make-up fast — if the delay was without a valid excuse — and it is not necessary for the feeding to coincide with the make-up; rather, it is permissible before, during, or after it. The expiation for delaying the make-up fast is: one mudd of food (approximately 750 grams), and what is more cautious: half a sa' (approximately 1.5 kilograms) for each day.