Remote Jamming at RADIOKOP SPAR

I live close to the SPAR at Radiokop in Roodepoort. For the THIRD time in the last month or so, I have experienced remote jamming at this centre. I have had my remote checked and there is nothing wrong with it, but when I stop at this particular SPAR, I am unable to lock my car. I have previously reported these incidents to the SPAR Manager, but no signs or warnings have been put up. I will not be going to that SPAR anymore - which is a pity - it's a nice SPAR and convenient for me - but as a Pensioner, I don't feel safe going there anymore.