Complex sentence: Altmann campaigned for many years for reform of the annuities market, in particular the sales process which she believed failed to ensure customers understood the risks of annuity purchase, even though it was irreversible, and did not help them find the right type of annuity.
Split into simpler sentences: Altmann campaigned for many years for reform of the annuities market: in particular the sales process. She believed the sales process failed to ensure customers understood the risks of annuity purchase (even though the transaction was irreversible) and did not help them find the right type of annuity.