Why did i get an ETAG

Topped up my etoll account on 04/01/2015 and a few days later the statement shows DISHONOURED, call the help Centre and asked what does DISHONOURED mean and they don't know and get the phone put down without any explanation. I emailed them a copy of my banks proof of payment and called them again the person at Help Centre completely in the dark, my account balance is running low and I ask them when will this reflect on my account and I am told ... wait for it... TOP UP AGAIN. I now have four different reference numbers regarding this mess