Dispute with Garanti Bank - please advise (Ankara)

I’m a British ex-pat currently living in Turkey and I need your advice about a dispute my wife is having with Garanti Bank.

My wife used to have a current account with a major Turkish high street bank (Garanti Bank) into which her salary was credited and from which her monthly bills were debited. She closed this account, cancelled all payments and withdrew the remaining balance two years ago, since when she’s thought no more of it. That was until last week when they called her on her mobile with a demand for more than Protected content . Assuming that there had been some sort of honest mistake she called the automated customer complaint line and explained the situation. A few hours later they called back upholding the charge.

This week we went to her old branch and spoke to one of the managers there. She looked at the account records and realised immediately the mistake. The bank clerk who had been supposed to close the account had failed to do so and left it open with a credit of 83 Kuruş. When a phone bill for 19 TL was received this was paid putting the account into debit. 2 years of interest fees, charges and tax meant that the bank was now owed more than Protected content . She then went on to tell us that there was however nothing she could do about this obvious mistake and that our only course of action was to contact their company lawyers.

The lawyers at first refused to talk to us saying we had to go through the automated company complaint line (which we had) or go to the branch (where we were calling from). When we got the branch manager to call, they finally agreed to talk to us only for them to rudely announce that they didn’t care about the situation, that we owed them money, and we should pay up or get a lawyer. When asked why they had not informed her about the debt earlier they claimed statements had been sent to her old work address. We had already spoken to the office manager at the old work address who denies this. They again rudely said they didn’t care.
I am at a loss as to how to proceed against such an attitude and was hoping someone here could offer us some advice.

Kind regards,
Chris Gyford.