SCAM.
Received a call stating that I owed money and then requesting my email address and bank details! Obviously, I did not give these and hung up. Over the following 3 months I received numerous phonecalls requesting that I call them back.
After the 3 months worth of calls I answered a call and told them that if they wish to contact me again they will need to send me a letter. They then proceeded to ask for my address! I said to them that surely they will be able to access my address from their system if I owe them a debt.
This was around 2-3 months ago. Since then, I have not received any more calls as I assume they realised I will not answer. I have, however, received many, many texts stating "Further to our letter, please contact us..." but still no letter! Obviously not, as they don't hold my address, or email address, or bank card details, as this is a scam.
I blocked one of the numbers that they used so since then I receive less texts, however, they continue to send threatening texts from another number which I now continue to ignore.
Please do not fall for this scam.