No response from query

<p>On the 30th of September 2015 I paid for my test done with Lancet.</p> <p>After 11 months I am getting statements saying I owe more money from that test.</p> <p>I phoned on the 23rd of August 2016 about this statement, and they told me they would investigate my case. Nothing happened since then. I phoned again on the 20th of Oct 2016, again they assured me that it would be investigated and that they will come back to me. Till today nothing has happend. </p> <p>I don't understand how Lancet can issue a statement 11 months after I already paid, and there is no contact after I have been told they would look into my case.</p> <p> </p>