Speed Point Nightmare!!

I went to the Shoprite in Kempton Park (Za_gp_sr_jansmuts) this morning, and as I was about to pay with my card, the speed point displayed ''No Connection''. I would be understanding if this was just a once off thing. But unfortunately the last time I went there the very same thing happened! The cashiers keep telling me the transaction would automatically reverse but this never happened in the first instance and I had to personally contact the bank to have the transaction reversed, at a fee. This is frustrating as now i have to contact my bank tomorrowto reverse today's transaction because the cashier and her superior insisted I pay cash as they won't allow me to leave with the grocery. I would suggest that management remove all speed points and write a big note that 'Only Cash' would be accepted as this is really annoying to say the least