The plot thickens...
Ok, so the former school refuses to hand over records on the basis of that they still have money owed to them (or so they say)
Sadly this is a standard practice in the industry. At an old school I used to work at we had several students of local and international background finish their final tests (GFPT, PPL, CPL, MECIR etc..) then leave town owing us thousands in debt. Did we ever see that money again, no!
Ever since then, our school refused to submit test paperwork and the like until all debts had been cleared.
All I can suggest is you march down there, speak to the CEO/CFI or even the chief pilot and clear up any discrepancies you have with your previous account and you might you'll have an easier time acquiring your documentation if you speak to them directly.