Pay my Fines **** SMS'

I keep on getting SMS' from random numbers for over a year now saying I have to pay a fine of R400, even threatened with legal action. I have since renewed my vehicle licence twice with no mention of a outstanding fine. When I search their website it comes up as having zero fines against me. I always pay my fines at Checkers if and when I receive it.

I smell a big fat **** here.