Whenever any retailer not maintaining a place of business in this State, to whom a permit to collect the tax hereby imposed has been issued pursuant to Section 6 hereof, fails to comply with any of the provisions hereof or any orders, rules or regulations of the Department prescribed and adopted hereunder, or when the Department considers the security furnished by such retailer to be inadequate or considers that the tax can be collected more effectively from persons using such property in this State, the Department may, upon notice and hearing as herein provided, by order revoke the permit issued to such retailer. No order authorized by this Section shall be made until the retailer is given an opportunity to be heard and to show cause why such order shall not be made, and he shall be given at least 7 days’ notice of the time, place and purpose of such hearing. The Department shall have the power in its discretion to issue a new permit pursuant to Section 6 hereof after such revocation.