It Was Almost Time for the Heeleys to Renew the Mortgage

It was almost time for the Heeleys to renew the mortgage on their home and they were considering their options. The mortgage was currently held by the Big Bank and the Heeleys were not satisfied with the service they had received from the Big Bank's mortgage staff. Recently, the local radio station had been airing commercials for the Little Bank, which suggested that people switch their mortgages to Little Bank to take advantage of better rates and more personal service. As a special incentive, the commercials stated that, for a limited time, for every mortgage over $50,000 which was brought to Little Bank from another financial institution, Little Bank would give the customer an all-expense-paid trip to Mexico. Feeling in need of a vacation, the Heeleys decided to take advantage of this incentive and made an appointment to see the manager of Little Bank. During their meeting the manager explained that the Mexico trip would be given on mortgages brought within the next month. The Heeleys mortgage did not expire at Big Bank for another six weeks, however the manager said it should not be a problem awarding them the trip for having made the commitment within the advertised period to transfer their mortgage. At the end of the six weeks, the Heeleys transferred their mortgage to Little Bank and delivered the paperwork needed by the bank to set up their trip. Several days later the Heeleys received a telephone call from the head office of the Little Bank informing them that they were not eligible to receive the trip as their mortgage had not been transferred within the offer period.
Discuss the legal issues that arise as a result of this case. What legal principles might the Heeleys and the bank apply to support their respective positions, and what would be the likely result should legal action ensue?