Dogtopia interview questions

My interview actually went really well and I received an offer. My issue is their failure to communicate after. I had discussed a full time position and start date with my interviewer which was not a problem. I was told there might be a second interview, depending on other candidates, and that’d I hear something in a week. Two days later, I received a job offer from the GM. The offer was wrong however, as it was a part time position with a way earlier start date than discussed. I told the GM I was thrilled to join the team but there seemed to be an error. I asked if this could be changed. He said “let me look into it”. A few days passed, I asked for an update and was told my interviewer would reach out “today or tomorrow”. I waited, nothing. I texted the GM again. He said he would have her give me a call. Nothing. Finally, I texted the GM again requesting communication. If there isn’t a full time place for me, please just say so. The GM, who had previously replied to texts the next minute, completely ignored me. I gave them a lot of grace. I knew they had a person on leave. I know they’re busy. But this is ridiculous. I felt like I was on some wild goose chase for simple communication following a first offer. It’s not hard to say “sorry, we can’t offer full time at the moment,” if that’s the case. Their repeated failure to communicate, after already sending me an offer, is unprofessional. Not to mention disrespectful. A company that treats their candidates this way won’t treat their employees any better.