Medical aid want us to apply modifier 0005

Practice Number ***Membership Number ***Account was paid in full originally and then Discovery Health reversed the amount of R7692.12 with the following reason : Reason for short- or non-payment304 | We have app**** modifier 0005 when we calculated the claim - according to industry standards. Month after month I'm trying to explain to Discovery Health Agents that there is no 0005 to be app**** as we only billed 1 procedure code. Month after month I must hear that my query was closed or that they escalate it again. So now I'm escalating the query to HelloPeter as it do not even help to email the Principal Officer of Discovery Health. Please sort this account out ASAP.