Answer:
Probably negative reinforcement in this case because positive reinforcement would have worked only if they were doing something which could be appreciated and encouraged.
Some negative reinforcement will be:
》Declaring the worst employer of the month and reducing their salary by 10%.
》Conducting a poll for customer feedback. Negative review could probably hurt their sentiments.
》Warning board such as"Work better else I will replace you by AI"
》Showing Cctv footage as a proof of how they are devaluing customer and doing a counterproductive job