southbay expressway bogus notice of toll evasion..... san diego California

I have recieve two notice of toll evasion .from san diego which I never use their toll at all since both that day I am at work or at home whick is in long beach area . I paid one with fine for 120 dolla,because I do not want to hasle with it ...now they send another one for another 40 dollar ...I decide to sell my car to have  no further problem ....they need to check and catch someone who use my license plate or correct their mistake and riemberse my money ....if i get it one more time may be I need to resort to the laywer to sue them

the license plat e they charge me is 7fox816 

they are not very helpful and no checking system to help with the complaint .....now I stuck with 200 dollar bill and may be more because they are not caring organization and irresponsible when trouble arise ...I never used their service but end up paying twice and may be more ...shame on southbay expressway  company