Expensive Yoco Device stops working after a few uses.

I Don't use my card reader much so it has been in a box in my desk for a long time. I took it out to charge it and check that all is well because I am doing a market in a few days and it gives some error. I have never dropped or mishandled the device and I paid roughly R2300 for mine, if I recall correctly. I see all devices are now under R1000 and I feel sick that I paid so much for something that now doesn't work. i now need a speed point urgently and I don't know what to do.