Handed over to lawyers for no reason

I moved jobs in December 2014, at which point we switched from my Discovery to my husband's work's Discovery with no gap in cover. In April I get a call from Discovery saying I will be handed over to lawyers if I do not pay an amount immediately. I complained since at no point since December did I get any correspondence or a call at least. They alleged they called me, but I never got a call. So I paid the amount. Now I get called again to say I have been handed over to lawyers and I have 48 hours to pay (the same amount I already paid) or else I will need to pay lawyers costs etc etc. <br> <br> Seeing as I did all I could when I was made aware of the outstanding debt I am livid to say the least. Do they think because they are a big company they can just charge and charge and charge? And ruin people's credit records? I called them afterwards and spent a frustrating 30 minutes trying to explain to some *********** agent there who I was. She kept calling me Mister and kept getting confused, called a manager who also was useless. On the system they seemed to have swopped my husband and I around, and couldn't fix it. So they clearly carried on with the comedy of errors. So frustrated!!