Fingerhut Reported to credit union payment not made after cancellation trial. Internet

Account paid in full early without late fees.  I did in sign up for a trial Fingerhut medical card for $1.00 but found when received it could not be used with my plan.  I cancelled well before the trial but Fingerhut continue to bill me. 

After not getting anywhere I agreed to pay $14.00 to clost account and afterward Fingerhut reported to credit agency that I was 90 days past due.  When paying Fingerhut agreed that there would be no further action if paid.  Now I'm unable to get student loans for my sons this semester, all for $14.00. 

Not only did they report incorrect negative payment history but they also listed the account as being sold to a collection agency.   Company refuse's to acknowledge my cancellation.  Credit ruined for $14.00 did not buy or charge anything from this company.