Answer:
Sleazy.
Step-by-step explanation
Sleazy is an English word used to describe something or someone that is considered to be of low quality, inferior, corrupt, dishonest and immoral.
Therefore, the right word to be used in describing a telemarketing firm that attempted to swindle naive customers is sleazy because they are corrupt, dishonest and lacking good morals as a business firm offering services to customers.
Hence, the Bureau of Consumer Affairs authorized the immediate closing of the sleazy and shady telemarketing firm for attempting to swindle naive
customers out of large sums of money.