Over Charged for Cashing My Check?

Is there any Federal or State laws governing check cashing businesses in the amount they are allowed to charge? I am 59 on SSI Disability (mentally challenged) received over $21,000. and was charged $2,000. for having my checked cashed. That is no chump change, I worked very hard for over 40+ years an to watch him verify the check, twice with three way phone calls, me authorizing him to cash it then he holds 60% of it for over three months. Please help.