I can't claim my unemployment fund

I am very disappointed.I signed a contract with these guys but they told me they will let me know when I must start working by the time they told me I must come to work I already found something else and I told them the manerger of the store told me that I must only write a letter to state that I'm resign so did so and that was in December 2021 but know when I got to the department of labour they told me that it's stated on the system that I'm still working there so the manerger did not do his work now I cant claim my unemployment fund because of them. And know they are acting as if it's my mistake.