Carbice interview questions

Interviewed here last year. Interview was simple and team seems very friendly, however, things became complicated after accepting the offer. They kept pushing back my start date and I received an offer for a six-month fellowship elsewhere. At this point, my start date for the marketing assistant role had been pushed back by three months and I asked Carbice HR if it would be possible for me to do the fellowship and then come back to this role after and HR expressed that would be fine and I would still be able to take the marketing role. When I finished the fellowship and reached out to Carbice HR again, they said the role was no longer open and that I could check in 3 months later. Very confusing and frustrating experience.