Any experience importing heavy items via air freight?

[DonJuane]

I went on my own and not with a carrier like Fed Ex or DSL to import a used "drive train" car part due to the 125Kg weight of the part. I am tied in red tape trying to import and pay taxes. I was assigned an agent to handle the import and a broker for taxes. All they seem to want to do is collect money and stall me while I pay a "warehousing fee" and in the process not give any true guidance through the process. I am about up to double what the used car part cost me and drowning in the red tape. My Spanish is not good enough to negotiate through this and actually I don't feel bad because a native speaker helped me and she said she was sorry but even she doesn't understand them. If anyone has experience with this process, I would appreciate the help. Thank you.