Concerned whether this account is a fraud activity

Send them a debt validation letter which is your right under the Fair Debt Collection Practices Act! They are required by law to validate that debt and cease all collection until they do! There is a template of that letter in the "do it yourself" section on this site! I am sure that once they see your letter that they will realize their error and leave you alone! If not you can sue them and collect 1000.00 for every violation they commit! RJM Aquisitions is a third party collector with a reputation that is much better than many collectors out there! It should work out OK for you.

Violations is limited to $1000 total, not for every violation.

Pull your credit report from the 3 bureaus and verify that this is not being reported against you. If it is on there then dispute it along with sending the DV letter. If the collector verifies the debt with the bureaus while the debt is in dispute via the DV letter then they violated the FCRA 1 time for each report or a total of 3 times which is $1,000 per violation. All of this is assuming they are reporting against your credit. If they do not have your SSN then it probably is not reported.