My previous employer stated it is my fault for all of this.....really?
If they over-paid you and you didn't spot it (you didn't do a balance check or read your statement and notice something odd), and therefore didn't pay it back, then technically that's your fault. And if you spend the money, they could possibly count it as theft.
Also, just because they had your email address, means nothing. Any sort of business like this would be dealt with by post. One reason why you should always set up mail forwarding with Royal Mail when you move house, so you don't miss important letters.
I got over paid once, but I spotted it on the payslip and put the money to one side so I could pay it back straight away.
I would check with your bank statements for the 3 months around the time you left the job, confirm that you were paid correctly or not. Then if they didn't overpay you, then take that to the court. If they did overpay you but you didn't notice, go to the courts, and argue that they didn't give you notice of the court case to allow you to settle the debt.
You don't want a CCJ on your record if you want to get any sort of credit in the next few years.
