Accutek Packaging Equipment interview questions

Had a great interview with the service team and was offered a job on the spot. The offer was below what I was looking for but after meeting the team I decided that this was the place I wanted to be. I got my paperwork and left, planning to come back in two weeks to start a new job. An hour later, I get a call from the manager I interviewed with and was told that the salary we agreed on wouldn't work for them and that I would need to take 25% less. I find it incredibly unprofessional that a large company like Accutek would not only pay below market rate but then have the audacity to backtrack on an agreement in an attempt to save a few dollars a month. Ridiculous.