MBD collections ****mers

MBD Attorneys are ********s and should be sued but apparently there is no legal recourse when dealing with this firm who absolutely refuse to stop harrassing me over money I never owed to them in the first place. I was handed over to MBD by Virgin Active for apparent non payment of my account with them but this was done in error. Virgin Active sent me a letter confirming as much which I have emailed twice to MDB. They still call me and tell me to pay them when I owe nothing. I have explained the situation many times. When I call the number provided in the email it doesn't even exist. They're con artists and shouldn't be allowed to operate at all.