Mis-sell Definition

mĭssĕl
mis-sell
verb
To sell (a service or investment) to a customer in a deceitful or misleading way.
American Heritage
To engage in fraudulent sales practices.
American Heritage

(UK, finance) To sell misleadingly, fraudulently, or in violation of laws or regulations.

The firm is defending itself against fresh allegations of pensions mis-selling.
Wiktionary