should i need to cancell my account in internet connection before leaving doha for good?

walk not, hanging an axe on your neck pls. we are accountable for whole aspect of our life., even if u go out without cancelling, it may automatically will be cancelled after accumulation of bills unpaid unnecessarily and you will be blacklisted in our system in the legal process Q-tel, that will constitute a problem in the future where ever u move in the middle east when a integrated technology of personal data will be implemented throughout the middle east and may complicate your comfort and conveninence further attempt to apply for a service from any point of gulf. Therefore, clear all liabilities and move out in white status is safe and good practice. Appreciated anyway your question,eventhough you have partially answered yourself.

Why you want to leave an open account behind. You have already pointed one possible problem, don’t take chances and cancel it. You might wish to comeback.

recently changed my telephone a/c to a new remote area. Cancelled everything I could think of! However when I arrived in the new house no new registration was necessary, still the old a/c worked and works still. Tried to change the orignal 12 year old login and password some years ago. No success, still the same! Don't think u will be stopped at the airport as yet because of this. But who knows, everything else for expats is changing. So who knows. QP previous(?) exit procedures requiring leavers to get a stamp confirming that they had no outstanding library loans with the National Library among equally unlikely things. Probably equally stupid procedures will be added. The best idea here is to react to some crook's theft from some company, who could have easily avoided loss by common sense checks and balances. by imposing restrictions on the 99% law abiding majority. Never mind it will all pass soon as the businesses affected, hotels have started the rush, complain about lost revenue.