Abdullah, you had a very rare experience, and according to Tunisian law, a criminal one.
Tunisian currency is
NOT a fully convertible currency as of yet, so therefore it can only be purchased inside of Tunisia.
Tunisian law prohibits the export and import of Tunisian bank notes or coins.
Tourists are expected to make foreign exchange transactions at authorized banks or dealers and to retain receipts for any and all dinars obtained. Under foreign currency regulations, a tourist can only reconvert Tunisian dinars into foreign currency that which amounts to
less than 5,000TND.
Tunisian law does permit the export of foreign currency that was DECLARED when entering Tunisia (you will get a receipt for your money and it will state how much you brought in country). Declaring foreign currency on entering Tunisia and obtaining a receipt for dinars purchased thereafter will facilitate reconverting dinars to your original currency. You will need to keep
ALL receipts of monetary transactions for presentation when leaving the country. You will have no problems leaving the country with foreign currency that you never converted into TND at all.
You can read more about the law from and government embassy website and the Central Bank of Tunisia website under Exchange Rate Regulation.
http://www.bct.gov.tn/bct/siteprod/e...ementation.jsp