Wow, how is it that the taxes raised this much!?

Ok, So I had a levy on my account from the board of equalization. They told me after that I owed $800 more and told me they would send me a breakdown and for what. I never got it. A year later I receive a bill for $3600 (went up that much from the $800 in a year) THEN two weeks later I got another letter saying its $5907 ...WTF! this is outrageous and doesnt make sense...I try to get ahold of them and they never return my phone calls...What do I do? why did it increase by $5000 in one year...