i am an owner operator - looking for info

do you know or know how i can find out how much a company can legally take in percentage from an owner operator? it started out my company paying me 70% of load plus fuel surcharge,we pay for permits and everything(bought a lot of annuals saved tons of money that way. now our company started taking the money out of the load (way more than they need)for the permits(there goes our profit)keeping the extra not spent and taking a percentage point away every time a dot shuts you down. doesn't matter the reason(company fault or yours).is this legal? please let me know if you have any info on this subject.