After 30 years of faithful payment, Obvion wants t...

After 30 years of faithful payment, Obvion wants to continue collecting the interest until the accrued capital for repaying the savings mortgage has been received. In addition, they make no effort to receive that repayment on time. So this doesn't look like anything at all. The first best high school student can think of how to approach something as simple as that. But apparently they find that too much trouble at Obvion.
You also have nothing to do with customer service! Because, up to 2 times, they find it unnecessary to keep to the agreements they make.
And answering a letter in writing is apparently no longer possible either.