Questions & Answers
هل يتم حظري إذا قمت بالاستقالة قبل أن تختم تأشيرتي على جواز السفر؟
ثم حاولت الحصول على تأشيرة سياحة لدولة الإمارات العربية المتحدة، وأخبرتني الوكالة أنني على القائمة السوداء وتم رفض تأشيرتي. كان عقدي السابق غير محدد المدة.

Since you did not complete 6 months of probation, in all likelihood your employment can be terminated without warning.
Working on a visit visa: It is illegal for an individual to work without a valid employment contract/visa approved by the Ministry of Human Resources & Emiratisation ("Ministry of Labour") or the concerned Free Zone Authority.
You must have overstayed on a visit visa. If anyone overstays a visa, whether a tourist visa or after the termination of employment on the expiry of the grace period of 30 days, they are subject to daily fines and can also be deported under the Federal Law No. (6) of 1973 on Entry and Residence of Foreigners and under Federal Law No. (13) of 1996 Concerning Aliens Entry and Residence with a permanent/lifetime or temporary ban.